Sequence homology and structural similarity between cytochrome b of mitochondrial complex III and the chloroplast b6-f complex: position of the cytochrome b hemes in the membrane.

The amino acid sequences of cytochrome b of complex III from five different mitochondrial sources (human, bovine, mouse, yeast, and Aspergillus nidulans) and the chloroplast cytochrome b6 from spinach show a high degree of homology. Calculation of the distribution of hydrophobic residues with a "hydropathy" function that is conserved in this family of proteins implies that the membrane-folding pattern of the 42-kilodalton (kDa) mitochondrial cytochromes involves 8-9 membrane-spanning domains. The smaller 23-kDa chloroplast cytochrome appears to fold in five spanning domains that are similar to the first five of the mitochondria. Four highly conserved histidines are considered to be the likely ligands for the two hemes. The positions of the histidines along the spanning segments and in a cross section of the membrane-spanning alpha helices implies that two ligand pairs, His-82-His-197/198 and His-96-His-183, bridge the spanning peptides II and V, and the two hemes reside on opposite sides of the hydrophobic membrane core. In addition, the 17-kDa protein of the chloroplast b6-f complex appears to contain one or more of the functions of the COOH-terminal end of the mitochondrial cytochrome b polypeptide.     

Megakaryocyte dense granule components are sorted in multivesicular bodies

Recent studies suggest that multivesicular bodies are an intermediate stage in the formation of alpha-granules. In contrast, the kinetics and mode of appearance of dense granules during megakaryocytic maturation has remained poorly understood. Immunoelectron microscopy was used to monitor the appearance of dense granular markers (granulophysin and serotonin) on cryosections of human megakaryocytes (MKs) cultured from CD34(+) precursors. The monitoring was done on days 8 and 13 of culture. The data suggest that dense granules appear in immature MKs early during their maturation, concomitantly with alpha-granule formation. In MKs of intermediary maturation stage, granulophysin was mainly localized within dense granules and multivesicular bodies (MVBs), which were also labeled for serotonin. This study provides evidence that granulophysin is a dense granule marker in human MKs and that MVBs are an intermediary stage of dense granule maturation and probably constitute a sorting compartment between alpha-granules and dense granules. (Blood. 2000;95:4004-4007)     

Metabolic activity of phagocytosing granulocytes in chronic granulocytic leukemia: ultrastructural observation of a degranulation defect

The functional capacities of granulocytes in patients with chronic granulocytic leukemia are still a subject of controversy, probably due to the heterogeneity of the abnormalities observed from patient to patient. For a better definition of these abnormalities, 14 patients with untreated chronic granulocytic leukemia were studied. The patients were divided into three groups on the basis of the functional activities of their phagocytosing granulocytes. In four patients (group I), the granulocytes were normal in respect to particle ingestion, nitroblue tetrazolium (NBT)-stimulated reduction, cyanide-insensitive oxygen (O2) consumption, superoxide anion (O2-)-stimulated production, hydrogen peroxide (H2O2) production, and iodination. They also had a normal myeloperoxidase (MPO) content. In four patients (group III), the granulocytes were significantly defective in all of these activities. In the six remaining patients (group II), all the initial metabolic steps of the phagocytosing granulocytes (ingestion, NBT reduction, O2 consumption, O2-production, H2O2 production) were normal, as were the MPO content of the granulocytes, while iodination was strikingly decreased. These metabolic features suggested a degranulation defect which was observed ultrastructurally in the only patient studied among these six. The phagocytosing granulocytes of this patient did not degranulate and no deposits of MPO activity were seen in the phagosomes.     

Effects of yoga on cardiovascular disease risk factors: A systematic review and meta-analysis

Background

The aim of this review was to systematically assess and meta-analyze the effects of yoga on modifiable biological cardiovascular disease risk factors in the general population and in high-risk disease groups.

Methods

MEDLINE/PubMed, Scopus, the Cochrane Library, and IndMED were screened through August 2013 for randomized controlled trials (RCTs) on yoga for predefined cardiovascular risk factors in healthy participants, non-diabetic participants with high risk for cardiovascular disease, or participants with type 2 diabetes mellitus. Risk of bias was assessed using the Cochrane risk of bias tool.

Results

Forty-four RCTs with a total of 3168 participants were included. Risk of bias was high or unclear for most RCTs. Relative to usual care or no intervention, yoga improved systolic (mean difference (MD) = − 5.85 mm Hg; 95% confidence interval (CI) = − 8.81, − 2.89) and diastolic blood pressure (MD = − 4.12 mm Hg; 95%CI = − 6.55, − 1.69), heart rate (MD = − 6.59 bpm; 95%CI = − 12.89, − 0.28), respiratory rate (MD = − 0.93 breaths/min; 95%CI = − 1.70, − 0.15), waist circumference (MD = − 1.95 cm; 95%CI = − 3.01, − 0.89), waist/hip ratio (MD = − 0.02; 95%CI = − 0.03, − 0.00), total cholesterol (MD = − 13.09 mg/dl; 95%CI = − 19.60, − 6.59), HDL (MD = 2.94 mg/dl; 95%CI = 0.57, 5.31), VLDL (MD = − 5.70 mg/dl; 95%CI = − 7.36, − 4.03), triglycerides (MD = − 20.97 mg/dl; 95%CI = − 28.61, − 13.32), HbA1c (MD = − 0.45%; 95%CI = − 0.87, − 0.02), and insulin resistance (MD = − 0.19; 95%CI = − 0.30, − 0.08). Relative to exercise, yoga improved HDL (MD = 3.70 mg/dl; 95%CI = 1.14, 6.26).

Conclusions

This meta-analysis revealed evidence for clinically important effects of yoga on most biological cardiovascular disease risk factors. Despite methodological drawbacks of the included studies, yoga can be considered as an ancillary intervention for the general population and for patients with increased risk of cardiovascular disease.     

Pride in all Who Served: Development,Feasibility, and Initial Efficacy of a Health Education Group For LGBT Veterans

ABSTRACT

Many of the more than 1 million military veterans who identify as lesbian, gay, bisexual, and/or transgender (LGBT) have encountered “rejecting experiences in the military” and stigma from prior “Don’t Ask Don’t Tell” policies. Associated minority stress and social isolation have been linked to a disproportionate risk for depression and suicide, as well as a reluctance to seek medical care at Veterans Health Administration (VHA) facilities. This paper describes feasibility and preliminary outcomes of the newly developed, Pride in All Who Served Health Education Group created to meet the unique needs of sexual and gender minority veterans. The 10-week, closed, health education group (e.g., continuums of identity, military culture) enables open dialogue, fosters social connectedness, and empowers veterans to be more effective self-advocates within the healthcare system. Feedback from formative evaluations (n = 29 LGBT veterans and n = 25 VHA stakeholders) was incorporated before conducting a small scale, non-randomized pilot. Preliminary pre-post surveys (n = 18) show promise (i.e., Cohen’s d range ± 0.40 to 1.59) on mental health symptoms (depression/anxiety, suicidal ideation), resilience indicators (identity affirmation, community involvement, problem-focused coping), and willingness to access care within the VA system (satisfaction with VA services, perception of staff competence). Results suggest that the 10-week Pride Group may be an effective tool for addressing minority-related stress in LGBT veterans. A full-scale, randomized clinical trial of this intervention is needed to determine short and long-term impacts on clinical and healthcare access-related outcomes.     

Predictors of Health Behavior Change After an Integrative Medicine Inpatient Program

Background

Health behavior change can improve physical and psychosocial outcomes in internal medicine patients.

Purpose

This study aims to identify predictors for health behavior change after an integrative medicine inpatient program.

Method

German internal medicine patients' (N?=?2,486; 80 % female; 53.9?±?14.3 years) practice frequency for aerobic exercise (e.g., walking, running, cycling, swimming), meditative movement therapies (e.g., yoga, tai ji, qigong), and relaxation techniques (e.g., progressive relaxation, mindfulness meditation, breathing exercises, guided imagery) was assessed at admission to a 14-day integrative medicine inpatient program, and 3, 6, and 12 months after discharge. Health behavior change was regressed to exercise self-efficacy, stage of change, and health locus of control (internal, external-social, external-fatalistic).

Results

Short-term increases in practice frequency were found for aerobic exercise: short- and long-term increases for meditative movement therapies and relaxation techniques (all p?p?p?Conclusion Health behavior change after an integrative medicine inpatient program was predicted by self-efficacy, stage of change, and health locus of control. Considering these aspects might improve adherence to health-promoting behavior after lifestyle modification programs.     

Pancreatic fine‐needle aspiration cytology in patients < 35‐years of age: A retrospective review of 174 cases spanning a 17‐year period

Pancreatic lesions in young patients are relatively rare and, to our knowledge, the clinical value of pancreatic fine needle aspiration (FNA) in patients < 35 years of age has not been previously established by any other large retrospective studies. All pancreatic endoscopic ultrasound‐guided FNA (EUS‐FNA) cases performed on patients < 35 years of age were identified for a 17‐year period (1994–2010). All FNAs and all available correlating surgical pathology reports were reviewed. There were a total of 174 cases of pancreatic FNA performed on 109 females and 65 males under the age of 35 (range: 8–34, mean: 27 years). The FNA diagnoses included 37 malignant, 114 negative, nine atypia/suspicious, and 14 cases that were nondiagnostic. Of the 37 malignant FNA cases, the diagnoses included 18 pancreatic neuroendocrine tumors (PanNeT), 11 solid pseudopapillary neoplasms (SPN), five adenocarcinomas and three metastatic neoplasms. Histologic follow‐up was available in 22 of the 37 malignant cases diagnosed by FNA, and the diagnosis was confirmed in 21 cases. One pancreatoblastoma was misclassified as SPN on EUS‐FNA. False negative diagnoses were noted in three cases of low‐grade mucinous cystic neoplasm and one case of PanNeT. The most common type of neoplasms diagnosed by EUS‐FNA in patients < 35‐year old is PanNeT, followed by SPN with both tumors accounting for 75% of all the neoplasms encountered in this age group. The sensitivity and specificity for positive cytology in EUS‐FNA of the pancreas to identify malignancy and mucinous neoplasms were 90% and 100%, respectively. Diagn. Cytopathol. 2014;42:297–301. © 2013 Wiley Periodicals, Inc.     

Biome boundary maintained by intense belowground resource competition in world’s thinnest-rooted plant community

Recent findings point to plant root traits as potentially important for shaping the boundaries of biomes and for maintaining the plant communities within. We examined two hypotheses: 1) Thin-rooted plant strategies might be favored in biomes with low soil resources; and 2) these strategies may act, along with fire, to maintain the sharp boundary between the Fynbos and Afrotemperate Forest biomes in South Africa. These biomes differ in biodiversity, plant traits, and physiognomy, yet exist as alternative stable states on the same geological substrate and in the same climate conditions. We conducted a 4-y field experiment to examine the ability of Forest species to invade the Fynbos as a function of growth-limiting nutrients and belowground plant–plant competition. Our results support both hypotheses: First, we found marked biome differences in root traits, with Fynbos species exhibiting the thinnest roots reported from any biome worldwide. Second, our field manipulation demonstrated that intense belowground competition inhibits the ability of Forest species to invade Fynbos. Nitrogen was unexpectedly the resource that determined competitive outcome, despite the long-standing expectation that Fynbos is severely phosphorus constrained. These findings identify a trait-by-resource feedback mechanism, in which most species possess adaptive traits that modify soil resources in favor of their own survival while deterring invading species. Our findings challenge the long-held notion that biome boundaries depend primarily on external abiotic constraints and, instead, identify an internal biotic mechanism—a selective feedback among traits, plant–plant competition, and ecosystem conditions—that, along with contrasting fire regime, can act to maintain biome boundaries.

Recent findings (1) have demonstrated striking differences in plant rooting strategies across biomes worldwide, spawning the hypothesis that belowground competition for soil resources may be critical for maintaining biome boundaries (1, 2). This idea differs fundamentally from the historical notion that biomes primarily are delineated by extrinsic abiotic factors such as climate, geological parent material, or topography (3–8), or the more recent recognition that aboveground plant adaptations can promote fire-determined plant communities (9, 10).Belowground competition introduces a biotic mechanism that is intrinsic to the plant community, emerges from plant–plant contest for resources, and may help explain the puzzling observation that biome boundaries can persist independent of climate–geological factors (4, 10).Of central importance is Ma et al.’s (1) recent observation that root traits that are associated with resource uptake appear to differ across biomes with differing soil resource dynamics. Specifically, Ma et al. hypothesized that thin-rooted plant strategies may be favored in biomes with permanently or seasonally low soil resources. They reasoned that, in those conditions, natural selection would favor absorptive roots [i.e., first-order roots (1, 11)] with low diameter and high specific root length (i.e., root length per unit photosynthetic carbon invested), which, in turn, are traits that allow high root surface area and efficient exploration of resource-poor soils. Conversely, thick roots and low specific root length may remain competitive traits in biomes with abundant soil resources, despite reduced root surface area and less efficient soil exploration.Here we test Ma et al.’s hypothesis (1) using a unique study of root traits and plant–plant resource competition across the boundary of two distinct biomes within the Cape Floristic Region of South Africa: Fynbos and Afrotemperate Forest. We show in Fig. 1 and 12, 13), by slow decomposition and nutrient recycling (14), and by low stores of soil organic matter (15). In contrast, the Afrotemperate Forest biome is defined by a substantial accumulation of soil organic matter and organic-bound nutrients, which, in turn, supports high rates of plant–soil–nutrient recycling. Based on Ma et al.’s hypothesis, we would expect that these sharp differences in soil resource conditions would result in divergent belowground root traits across the biome boundary.Open in a separate windowFig. 1.Sharp differences in biodiversity, aboveground plant traits, and ecosystem properties across the South African Fynbos–Forest boundary. (A) Two neighboring biomes of the Cape Floristic Region—the Fynbos (62) and the Afrotemperate Forest (63)—form a sharp boundary despite perching on the same geological parent material (39). (B) Biodiversity: The hyperdiverse Fynbos harbors >7,000 plant species, of which the majority are endemic to South Africa (64). The Afrotemperate Forest, on the other hand, contains >450 species with less endemism (63). (C) Aboveground plant traits: Fynbos species generally possess thick and small leaves with a high carbon-to-nitrogen (C:N) ratio while Afrotemperate Forest species display thinner and larger leaves with a lower C:N ratio. In addition, Fynbos plant species possess traits that either enhance (e.g., waxes) or resist (e.g., thick bark) fire. For example, Fynbos vegetation contains high concentrations of flammable organic compounds (e.g., crude fat content) that can facilitate very hot fires (65). In contrast, Afrotemperate Forest species tend to be sensitive to fire and possess traits that suppress fire (e.g., high water content). (D) Ecosystem properties: Fynbos soils are exceedingly poor in soil carbon, nitrogen, and phosphorus contents. In contrast, the Afrotemperate Forest soil is characterized by a developed layer rich in carbon, nitrogen, and phosphorus, which facilitates active cycling of nutrients between plant and soil pools (66, 67).Table 1.Comparison of neighboring Fynbos and Afrotemperate Forest