Mindfulness-based therapy and behavioral activation: A randomized controlled trial with depressed college students.

Major Depressive Disorder (MDD) manifests in 20-30% of college students, with increased incidence in recent decades. Very limited research has assessed the efficacy of evidence-based interventions for MDD in college students. Mindfulness-Based Therapy (MBT) and Behavioral Activation (BA) are two interventions with significant potential to meet demands of college counseling clinics and effectively treat college students with MDD. This study utilized a randomized controlled research design (n = 50) to examine the efficacy of four-sessions of abbreviated MBT and BA relative to a wait-list control condition with depressed college students. Intent-to-treat data analyses on depression outcome measures suggested both treatments were superior to the control group. There were significant pre-post treatment improvements across measures of depression, rumination, stress, and mindfulness, gains largely maintained at 1-month follow-up. Neither active treatment effectively reduced somatic anxiety. Both treatments generally had moderate-strong effect sizes relative to the control group, and based on depression response and remission criteria, 56-79% of patients exhibited clinically significant improvement. Based on reliable change indices, 75-85% experienced clinically significant reductions in depression. There was strong therapist competence and adherence to treatment protocols and high patient satisfaction with both interventions. Study limitations and implications for the assessment and treatment of depressed college students are discussed.

Pretreatment depression severity in breast cancer patients and its relation to treatment response to behavior therapy.

OBJECTIVE: Major depressive disorder is prevalent in breast cancer patients. There is a paucity of research on variables associated with depression severity and the link between depression severity and response to psychotherapy. To provide optimal mental health services to breast cancer patients, examining correlates of depression severity and its relation to treatment response is critical. METHOD: In the context of a randomized trial of behavior activation and problem-solving therapy for depressed breast cancer patients, this study evaluated demographic (marital status, age, education), psychosocial (social support, environmental reward, anxiety, number of coexistent anxiety disorders), and cancer-related (bodily pain, length of diagnosis, cancer stage) variables associated with pretreatment depression severity. Second, the relation of pretreatment depression severity with posttreatment and 12-month response and remission was assessed. RESULTS: For pretreatment depression severity, the overall regression model accounted for 40% of the variance, F(5, 74) = 9.87, p < .001. Less environmental reward and greater somatic anxiety were significantly and uniquely associated with depression severity. Depression severity was unrelated to treatment remission but was a significant moderator of treatment response at posttreatment and 12-month follow-up; individuals with higher depression severity were more responsive to therapy. For patients treated with behavior activation, environmental reward significantly mediated the relationship between pre- and posttreatment depression. CONCLUSIONS: Consistent with behavioral models of depression, less environmental reward and greater anxiety might influence depression severity in breast cancer patients. Data support the efficacy of behavior therapy for breast cancer patients, particularly those with more severe depression.

Dynamics and kinetics of structure formation in molecularly tethered fluorocarbon/hydrocarbon amphiphiles.

Biphasic fluorocarbon/hydrocarbon amphiphiles tethered to cores at distances commensurate with their packing requirement can provide thermodynamic pathways toward equilibrium. This contrasts with the analogous semifluorinated alkanes. The dynamics of a fluorous biphasic hexa(3,5-substituted-phenyl)benzene (HPB) is studied with dielectric spectroscopy as a function of temperature and pressure in comparison to the parent biphasic diphenylacetylene (DPA). Dielectric spectroscopy is a sensitive probe of the fluorocarbon environment through the end C-F dipole. Four dielectrically active processes were observed that associate with the CF(3) environment within the different phases (isotropic, liquid-like lamellar, solid lamellar, glassy state). Pressure facilitates the construction of the equilibrium phase diagram. The kinetic pathways to fluorocarbon organization are explored by pressure-jump experiments. A highly cooperative process was found that is atypical of a nucleation and growth process expected for first-order transitions.

Subtype analysis of Blastocystis isolates in Swedish patients.

Blastocystis is a genetically diverse and widespread intestinal parasite of animals and humans with controversial pathogenic potential. At least nine subtypes of Blastocystis have been found in humans. The genetic diversity of Blastocystis was examined in stool samples from 68 patients from the Stockholm area, Sweden. Blastocystis was identified by light microscopy, and subtyped by sequencing the 5'-end of the small subunit ribosomal RNA gene. Five Blastocystis subtypes were identified in the 63 patients whose samples were successfully subtyped: ST1 (15.9%), ST2 (14.3%), ST3 (47.6%), ST4 (20.6%), and ST7 (1.6%). ST3 was more common in males compared to females (P=0.049). Comparative molecular analysis of Blastocystis sequences revealed intra-subtype variations within the identified subtypes with the exception of ST4. Among ST4 sequences in this study, as well as in the majority of human GenBank sequences, a limited genetic diversity was found compared to what was found among the other common subtypes (ST1, ST2 and ST3). The relative prevalence of ST4 in this study was comparable to the overall distribution of ST4 in European cohorts (16.5%). This contrasts with the sparse reports of ST4 in studies from other continents, which may indicate that the distribution of this subtype is geographically heterogeneous.

Surveillance for Listeria monocytogenes and listeriosis, 1995-2004.

Canadian cases and outbreaks of illness caused by Listeria monocytogenes between 1995 and 2004 were assessed. Isolates (722 total) were characterized by serotyping, and pulsed-field gel electrophoresis (PFGE) was performed to provide a means of detecting case clusters. Rates of listeriosis remained fairly consistent during the period of study, and patient characteristics were similar to those seen in studies of other populations. Most isolates were obtained from blood and cerebrospinal fluid, although during some outbreak investigations isolates were also obtained from stools. Serotype 1/2a predominated in isolates from patients in Canada, followed by serotypes 4b and 1/2b. Outbreaks caused by L. monocytogenes that occurred during the period of study were caused by isolates with serotypes 1/2a and 4b. A retrospective analysis of PFGE data uncovered several clusters that might have represented undetected outbreaks, suggesting that comprehensive prospective PFGE analysis coupled with prompt epidemiological investigations might lead to improved outbreak detection and control.

Cryptic diversity in intestinal protists.

In the past few years our understanding of genetic variation within and between species of intestinal parasitic protists has changed significantly. New species names have been assigned and others have been dropped in response to new data. In this review, I summarise these findings and discuss their implications for future studies. In several cases the findings suggest that caution needs to be exercised to prevent premature conclusions being reached.

Thermodynamic, structural, and nanomechanical properties of a fluorous biphasic material.

The dynamics of the amphiphilic semifluorinated F(CF2)12(CH2)12H (F12H12) alkane that undergoes two condensed phase transitions have been investigated by Brillouin light spectroscopy, shear rheometry, small- (SAXS) and wide-angle (WAXS) X-ray scattering, and thermodynamic PVT measurements. The solid (I)-solid (II) transition (Ts) is marked by a stronger temperature dependence of the sound velocity in phase II and by a 2 orders of magnitude drop of the shear modulus. Between the Ts and the melting transition (Tm), the presence of two phonons implies a coexistence of solid (II) and amorphous (liquid) regions in the submicrometer range at thermal equilibrium as revealed by the SAXS pattern of a single reflection superimposed on a very broad amorphous halo. This intriguing finding of a transient, very slow (over 10 h) solid/liquid coexistence within phase II is rationalized by a two-stage mechanism for melting of the smectic phase (II) of F12H12. A refinement of the known packing motifs for the two solid-state structures is proposed.

Structure and content of the Entamoeba histolytica genome.

The intestinal parasite Entamoeba histolytica is one of the first protists for which a draft genome sequence has been published. Although the genome is still incomplete, it is unlikely that many genes are missing from the list of those already identified. In this chapter we summarise the features of the genome as they are currently understood and provide previously unpublished analyses of many of the genes.

Dietary factors in relation to the distribution of duodenal ulcer in India as assessed by studies in rats.

BACKGROUND: The prevalence of duodenal ulcer is less in the northern wheat-eating regions of India and China than in the southern rice-eating areas. METHODS AND RESULTS: Experiments were conducted on rat peptic ulcer models in which controls were fed on either known ulcerogenic rice or rice plus tapioca diets or on non-ulcerogenic stock diet. By using an ulcerogenic diet and pyloric ligation, unrefined wheat, wheat bran and their respective oils were protective against ulceration. Refined wheat, wheat germ and its oil were not protective. Freshly milled rice and unmilled rice were protective, but stored rice bran and its oil increased the ulceration. Fresh rice bran oil was not ulcerogenic, but on storage, it became ulcerogenic. By using stock diet and alcohol-induced ulceration, the findings with whole wheat oil, wheat bran and wheat germ oil were confirmed. Rats fed on the stock diet subjected to pyloric ligation developed ulcers following intragastric injection of stored rice bran oil. This ulcerogenicity was counteracted by whole wheat oil. CONCLUSION: These results suggest that the factor of diet may well explain the regional differences in the prevalence of duodenal ulceration between North and South India and China where other etiologic factors are similar.

Genetic Variation among Human Isolates of Uninucleated Cyst-Producing Entamoeba Species.

Twelve human infections with Entamoeba spp. producing uninucleated cysts were studied. DNA was extracted from infected feces and used to amplify part of the ameba small-subunit rRNA gene. Sequence analysis identified four distinct types of Entamoeba, all of which are related to Entamoeba polecki and E. chattoni and two of which have not been reported previously. Whether these genetic types represent different species is unclear. We propose that the agent of all human infections with uninucleated cyst-producing Entamoeba species be reported as "E. polecki-like."

Isolation and characterization of polymorphic DNA from Entamoeba histolytica.

An important gap in our understanding of the epidemiology of amebiasis is what determines the outcome of Entamoeba histolytica infections. To investigate the possible existence of invasive and noninvasive strains as one factor, the ability to differentiate individual isolates of E. histolytica is necessary. Two new loci containing internal repeats, locus 1-2 and locus 5-6, have been isolated. Each contains a single repeat block with two types of related direct repeats arranged in tandem. Southern blot analysis suggests that both loci are multicopy and may themselves be arranged in tandem arrays. Three other previously reported, internally repetitive loci containing at least two repeat blocks each with one or more related repeat units were also investigated. PCR was used to study polymorphism at each of these loci, which was detected to various degrees in each case. Variation was seen in the total number of bands obtained per isolate and their sizes. Nucleotide sequence comparison of loci 1-2 and 5-6 in five axenic isolates revealed differences in the number of repeat units, which correlated with the observed PCR product size variation, and in repeat sequence. Use of multiple loci collectively allowed differentiation of a majority of the 13 isolates studied, and we believe that these loci have the potential to be used as polymorphic molecular markers for investigating the epidemiology of E. histolytica and the potential existence of genetically distinct invasive and noninvasive strains.

Cryptic genetic diversity in Dientamoeba fragilis.

Uncertainty surrounding the role of Dientamoeba fragilis in human disease could be due in part to the existence of pathogenic and nonpathogenic variants. Evidence for two genetically distinct forms was obtained using PCR-restriction fragment length polymorphism analysis of ribosomal genes. Future studies in humans will need to take D. fragilis diversity into account.

The evolution of Entamoeba, a cautionary tale.

In addition to its medical importance, the parasite Entamoeba histolytica has been studied by evolutionary biologists because of its unusual structural and biochemical features. Recent molecular data have revealed that many of our assumptions regarding the relationships of the organism and its relatives have been incorrect.

Duodenal ulcer prevalence: experimental evidence for the possible role of dietary lipids.

BACKGROUND AND AIMS: Mapping the geographical distribution of duodenal ulcer in relation to staple diets, and experiments on animal peptic ulcer models suggested that the lipid fraction in certain foodstuffs had a protective effect which was most marked in the lipid obtained from Horse gram (Dolichos biflorus). Lipid obtained from stored polished rice or rice bran was ulcerogenic. Further animal experiments were designed to investigate the protective and healing effects of Horse gram lipid (HGL) against peptic ulceration. METHODS: Three effects were investigated in rats: (i) the protective effect of HGL on peptic ulceration produced by using pyloric ligation in combination with South Indian diet or rice bran oil, or by cysteamine, alcohol or aspirin; (ii) the effect of HGL on mast cell degranulation in response to pyloric ligation and rice bran oil; and (iii) the healing effect of HGL on acute gastric ulceration produced by alcohol, on chronic gastric ulceration produced by topical acetic acid or on chronic duodenal ulcer following cysteamine. RESULTS: Horse gram lipid was shown to be protective and to promote ulcer healing in all the models used. Mast cell degranulation was inhibited. CONCLUSION: The experiments confirm the presence of a lipid in certain staple foods that have protective and healing properties in experimental peptic ulcer animal models. The differences in the prevalence of duodenal ulceration between different regions in some developing countries with a high prevalence of Helicobacter pylori infection might be explained by the presence or absence of protective lipids or ulcerogenic factors in the staple diet.

A mutant Shiga-like toxin IIe bound to its receptor Gb(3): structure of a group II Shiga-like toxin with altered binding specificity.

BACKGROUND: Shiga-like toxins (SLTs) are produced by the pathogenic strains of Escherichia coli that cause hemorrhagic colitis and hemolytic uremic syndrome. These diseases in humans are generally associated with group II family members (SLT-II and SLT-IIc), whereas SLT-IIe (pig edema toxin) is central to edema disease of swine. The pentameric B-subunit component of the majority of family members binds to the cell-surface glycolipid globotriaosyl ceramide (Gb(3)), but globotetraosyl ceramide (Gb(4)) is the preferred receptor for SLT-IIe. A double-mutant of the SLT-IIe B subunit that reverses two sequence differences from SLT-II (GT3; Gln65-->Glu, Lys67-->Gln, SLT-I numbering) has been shown to bind more strongly to Gb(3) than to Gb(4). RESULTS: To understand the molecular basis of receptor binding and specificity, we have determined the structure of the GT3 mutant B pentamer, both in complex with a Gb(3) analogue (2.0 A resolution; R = 0.155, R(free) = 0.194) and in its native form (2.35 A resolution; R = 0.187, R(free) = 0.232). CONCLUSIONS: These are the first structures of a member of the medically important group II Shiga-like toxins to be reported. The structures confirm the previous observation of multiple binding sites on each SLT monomer, although binding site 3 is not occupied in the GT3 structure. Analysis of the binding properties of mutants suggests that site 3 is a secondary Gb(4)-binding site. The two mutated residues are located appropriately to interact with the extra betaGalNAc residue on Gb(4). Differences in the binding sites provide a molecular basis for understanding the tissue specificities and pathogenic mechanisms of members of the SLT family.