Safety and tolerability of Pau d' Arco (Tabebuia avellanedae) for primary dysmenorrhea: A single-arm, open-label trial on adults ages 18-45

Objectives

To evaluate the safety and tolerability of encapsulated Tabebuia avellanedae in generally healthy women aged 18-45 with primary dysmenorrhea.

Methods

A single arm, open-label trial was conducted in which 1050 mg/day of encapsulated Tabebuia avellanedae (Pau d'Arco) was administered to twelve healthy women aged 18-45 for eight weeks. The primary outcome was safety and tolerability as measured by standardized adverse events scales and serial collection of laboratory markers to assess general health, prothrombin times, and the presence or absence of anemia. Secondary outcomes included pain intensity, quality of life, and pain interference measured by the Visual Analog Scale (VAS), the Patient-Reported Outcomes Measurement Information System (PROMIS) 29 survey, and the PROMIS Visual Sexual Function and Satisfaction: Interfering Factors survey, respectively. Exploratory outcomes included serum concentration of high-sensitivity C-reactive protein as a marker of systemic inflammation.

Results

Seventy-five percent of participants (n = 9/12) completed the study. Seventy-five percent of study participants (n = 9/12) reported an adverse event, most of which were characterized as mild, and none were determined to be a Food and Drug Administration (FDA) serious adverse event. Most laboratory markers stayed within normal limits throughout the study period with a few clinically mild abnormalities. There was a significant decrease in pain intensity compared to baseline after the first dose (p < .01), after 4 weeks of treatment (p < .01), and after 8 weeks of treatment (p < .01). Over the 8-week intervention period, pain interference, quality of life, and sexual function and satisfaction scores improved nonsignificantly and hs-CRP decreased nonsignificantly.

Conclusions

Tabebuia avellanedae supplementation of 1050 mg/day dose for eight weeks in generally healthy women aged 18-45 with primary dysmenorrhea was generally safe, associated with moderate tolerability, and associated with significant improvements in pain intensity scores. Future studies examining the safety and efficacy of Tabebuia avellanedae on primary dysmenorrhea are warranted.

Antibiotic-Loaded Polymersomes for Clearance of Intracellular Burkholderia thailandensis

Melioidosis caused by the facultative intracellular pathogen Burkholderia pseudomallei is difficult to treat due to poor intracellular bioavailability of antibiotics and antibiotic resistance. In the absence of novel compounds, polymersome (PM) encapsulation may increase the efficacy of existing antibiotics and reduce antibiotic resistance by promoting targeted, infection-specific intracellular uptake. In this study, we developed PMs composed of widely available poly(ethylene oxide)-polycaprolactone block copolymers and demonstrated their delivery to intracellular B. thailandensis infection using multispectral imaging flow cytometry (IFC) and coherent anti-Stokes Raman scattering microscopy. Antibiotics were tightly sequestered in PMs and did not inhibit the growth of free-living B. thailandensis. However, on uptake of antibiotic-loaded PMs by infected macrophages, IFC demonstrated PM colocalization with intracellular B. thailandensis and a significant inhibition of their growth. We conclude that PMs are a viable approach for the targeted antibiotic treatment of persistent intracellular Burkholderia infection.

Foot shock facilitates reward seeking in an experience-dependent manner

Animals organize reward seeking around aversive events. An abundance of research shows that foot shock, as well as a shock-associated cue, can elicit freezing and suppress reward seeking. Yet, there is evidence that experience can flip the effect of foot shock to facilitate reward seeking. Here we examined cue suppression, foot shock suppression and foot shock facilitation of reward seeking in a single behavioural setting. Male Long Evans rats received fear discrimination consisting of danger, uncertainty, and safety cues. Discrimination took place over a baseline of rewarded nose poking. With limited experience (1-2 sessions), all cues and foot shock suppressed reward seeking. With continued experience (10-16 sessions), suppression became specific to shock-associated cues, foot shock briefly suppressed, then facilitated reward seeking. Our results provide a means of assessing positive properties of foot shock, and may provide insight into maladaptive behaviour around aversive events.

Maternalism: a healthy alliance for recovery and transition in eating disorder services

ACCESSIBLE SUMMARY

The therapeutic relationship is pivotal to mental health nursing, but very little is known about how it is experienced in adult eating disorder services. This paper reports on a research project that sought to discover how the therapeutic relationship is experienced between care workers and women with anorexia nervosa in an adult eating disorder service. Both care workers and women spoke of a relationship that had similarities to the mother-daughter relationship, that it felt therapeutic and that it was in keeping with a professional and compassionate nursing approach. These findings provide new insight. Maternalism is seen as a positive, nurturing and transient relationship that ensures the safety of the person and promotes recovery and transition to eventual independence.

ABSTRACT

This paper reports on a UK interpretative phenomenological research study that aimed to explore the lived experience of the relationship between women with anorexia and their care workers in the context of a specialist eating disorder (ED) unit. Here, the concept of maternalism as a phenomenon occurring within the therapeutic relationship in specialist ED units is discussed. Consideration is given to the parallel roles of the health care worker whose duty it is to protect, preserve life and to promote health and that of a mother/guardian. Although seemingly simplistic, the comforting, soothing and nurturing techniques that are used by the workers to diffuse distress and help the person feel cared for have many similarities to 'mothering'. Hence, a maternalistic approach that provides a sense of security and nurturing can be a compassionate way to facilitate hope and a route out of their anorexia into recovery, in the same way that good parenting can facilitate maturation and independence.

A multi-tiered intervention to address behavioural and cognitive changes after diagnosis of primary brain tumour: a feasibility study

PURPOSE

Untreated behavioural and cognitive changes after primary brain tumour (PBT) can result in challenging behaviours (CBs), with limited documentation on treatment approaches. This study explored the feasibility of employing a Behavioural Consultancy approach to manage CBs, targeting individuals with PBT, family and treating staff.

METHODS

Participants were patients and families of two hospitals and health professionals from cancer/neurological services. A single-case experimental design piloted skill-based training and environmental changes in managing socio-behavioural impairments in a person with a low grade astrocytoma. A half-day workshop to train family members (n = 7) in compensatory strategy use to manage CBs after PBT was piloted. Finally, a 1-day workshop was provided to 43 health professionals in managing CBs after PBT. For both workshops, a pre-post impact evaluation was conducted employing a purpose-designed Strategies Use Measure.

RESULTS

All three interventions demonstrated positive results. The single case showed a 71% decrease in the target behaviour (time spent talking) post-intervention. Some attrition to these gains was observed at two follow-up time points (3 and 5 months). Participants from both workshops demonstrated significant post-intervention increases in perceived knowledge of Strategy Use (family members z = 2.03, p < 0.05; health professionals z = 4.95, p < 0.00; Wilcoxon signed-rank test).

CONCLUSIONS

These initial studies highlight the potential of employing an integrated multi-tiered intervention based on a Behavioural Consultancy model to manage CBs after PBT.

An angel on my shoulder: a study of relationships between women with anorexia and healthcare professionals

Adults with anorexia are an under-researched group because the usual focus is on adolescents. The relationships that occur between healthcare professionals and adults with anorexia are often challenging, because they do not necessarily agree on the goals of treatment. The therapeutic relationship is widely recognized as crucial to care, even healing and restorative in its own right but problematic in this setting. This is a phenomenological study of how therapeutic relationships are negotiated and maintained in a day care service. Six women with anorexia nervosa and seven of their healthcare professionals were interviewed in the care setting to explore their lived experience of their relationships. Six important themes emerged from the interviews: the authenticity of the relationship, safety, the externalization of the eating disorder, recovery measured in kilos, the power of hope and optimism and the use and acceptance of maternalism in the care setting. Findings suggest that patients appreciated the safety and security of care, but some were using the service as respite rather than recovery. Patients saw goals and tasks related directly to weight gain as irrelevant to their main concerns, but engagement with people who provided a secure, nurturing and maternalistic context for safety and optimism was seen as supportive.

Methods for peak assignment in low-resolution multidimensional NMR cross-correlation relaxometry

Several NMR protocols are presented for assigning peaks in complex T1-T2 spectra, including the effects of varying the spectrometer frequency and the CPMG pulsing rate. Extensions into a third dimension based on chemical-shift; diffusion- and field-cycled weighted T1-T2 cross-correlation methods are also explored as a means of peak assignment. We illustrate the power of these novel techniques with reference to simple aqueous sucrose solutions, but the methodology should be generally applicable.

Mimulus is an emerging model system for the integration of ecological and genomic studies

The plant genus Mimulus is rapidly emerging as a model system for studies of evolutionary and ecological functional genomics. Mimulus contains a wide array of phenotypic, ecological and genomic diversity. Numerous studies have proven the experimental tractability of Mimulus in laboratory and field studies. Genomic resources currently under development are making Mimulus an excellent system for determining the genetic and genomic basis of adaptation and speciation. Here, we introduce some of the phenotypic and genetic diversity in the genus Mimulus and highlight how direct genetic studies with Mimulus can address a wide spectrum of ecological and evolutionary questions. In addition, we present the genomic resources currently available for Mimulus and discuss future directions for research. The integration of ecology and genetics with bioinformatics and genome technology offers great promise for exploring the mechanistic basis of adaptive evolution and the genetics of speciation.

Apoptosome dependent caspase-3 activation pathway is non-redundant and necessary for apoptosis in sympathetic neurons

Although sympathetic neurons are a well-studied model for neuronal apoptosis, the role of the apoptosome in activating caspases in these neurons remains debated. We find that the ability of sympathetic neurons to undergo apoptosis in response to nerve growth factor (NGF) deprivation is completely dependent on having an intact apoptosome pathway. Genetic deletion of Apaf-1, caspase-9, or caspase-3 prevents apoptosis after NGF deprivation, and importantly, allows these neurons to recover and survive long-term following readdition of NGF. The inability of caspase-3 deficient sympathetic neurons to undergo apoptosis is particularly striking, as apoptosis in dermal fibroblasts and cortical neurons proceeds even in the absence of caspase-3. Our results show that in contrast to dermal fibroblasts and cortical neurons, sympathetic neurons express no detectable levels of caspase-7. The strict requirement for an intact apoptosome, coupled with a lack of effector caspase redundancy, provides sympathetic neurons with a markedly increased control over their apoptotic pathway.

Motional relativity and industrial NMR sensors

We explore the implications of motional relativity in NMR and show that sample translation can be used to acquire NMR signals without the need for pulsed RF excitation or pulsed magnetic field gradients. Novel single-shot, on-line NMR acquisition protocols for samples being conveyed at high speed are discussed and preliminary results using a low-cost, on-line prototype NMR sensor are presented.

A low-field, low-cost Halbach magnet array for open-access NMR

A working prototype of a novel low-cost Halbach-array-based NMR system is described. The new design provides open access to the sample relative to conventional NMR magnet designs and this facilitates the simultaneous use of multi-sensor techniques on the same sample, in which NMR/MRI can potentially be combined with other spectroscopies such as impedance spectroscopy, laser scattering and rheological experiments.

Microstructural effects on microbial survival: phase-separating dextran solutions

Evolving microstructure in a model dextran solution is shown to exert a major influence on the survival of Escherichia coli K-12 frag 1 and Salmonella typhimurium LT2. The microstructure results from microscopic phase separation, which develops over several hours resulting in hardening of the solution into a glassy state. The microstructure is characterized by an array of physical methods including image analysis, electron spin resonance and bulk rheology, and it is shown that bacterial survival depends on the formation of microscopic. water-rich domains and not primarily on bulk water activity or hardness.

Effective particle-mediated vaccination against mouse melanoma by coadministration of plasmid DNA encoding Gp100 and granulocyte-macrophage colony-stimulating factor

Particle-mediated gene delivery was used to immunize mice against melanoma. Mice were immunized with a plasmid cDNA coding for the human melanoma-associated antigen, gp100. Murine B16 melanoma, stably transfected with human gp100 expression plasmid, was used as a tumor model. Particle-mediated delivery of gp100 plasmid into the skin of naïve mice resulted in significant protection from a subsequent tumor challenge. Co-delivery of murine granulocyte-macrophage colony-stimulating factor (GM-CSF) expression plasmid together with the gp100 plasmid consistently resulted in a greater level of protection from tumor challenge. The inclusion of the GM-CSF plasmid with the gp100 DNA vaccine allowed a reduction in the gp100 plasmid dose required for antitumor efficacy. Protection from tumor challenge was achieved with as little as 62.5 ng of gp100 DNA per vaccination. Tumor protection induced by the gp100 + GM-CSF gene combination was T cell mediated, because it was abrogated in vaccinated mice treated with anti-CD4 and anti-CD8 monoclonal antibodies. In addition, administration of the gp100 + GM-CSF DNA vaccine to mice bearing established 7-day tumors resulted in significant suppression of tumor growth. These results indicate that inclusion of GM-CSF DNA augments the efficacy of particle-mediated vaccination with gp100 DNA, and this form of combined gp100 + GM-CSF DNA vaccine warrants clinical evaluation in melanoma patients.

Surgery of amphibians

This article is an introduction to common amphibian surgical techniques. No overwhelming obstacles preclude incorporating amphibian surgeries into the repertoire of veterinary clinicians. With the proper tools and reference materials and a little practice, the skills needed may be readily acquired.

Analysis of the N gene hypersensitive response induced by a fluorescently tagged tobacco mosaic virus

The hypersensitive response (HR) triggered on Nicotiana edwardsonii by tobacco mosaic virus was studied using a modified viral genome that directed expression of the green fluorescent protein. Inoculated plants were initially incubated at 32 degrees C to inhibit the N gene-mediated HR. Transfer to 20 degrees C initiated the HR, and fluorescent infection foci were monitored for early HR-associated events. Membrane damage, which preceded visible cell collapse by more than 3 h, was accompanied by a transient restriction of the xylem within infection sites. Following cell collapse and the rapid desiccation of tissue undergoing the HR, isolated, infected cells were detected at the margin of necrotic lesions. These virus-infected cells were able to reinitiate infection on transfer to 32 degrees C, however, if maintained at 20 degrees C they eventually died. The results indicate that the tobacco mosaic virus-induced HR is a two-phase process with an early stage culminating in rapid cell collapse and tissue desiccation followed by a more extended period during which the remaining infected cells are eliminated.

Basic husbandry and clinical assessment of the amphibian patient

The veterinarian presented with an amphibian patient must be prepared to assess both the animal's medical condition and its husbandry record; good health is inextricably linked to proper care and diet. This article provides the clinician with guidelines for maintaining amphibians in captivity, including information on climate control and lighting, housing and cage enrichment, and nutrition. The article also covers questions to ask when taking a history, methods of restraint, and practical advice on the equipment and techniques used to conduct a complete physical examination of the amphibian patient.

Microstructural characterization of starch systems by NMR relaxation and Q-space microscopy

Nuclear magnetic resonance (NMR) relaxation and q-space diffusion measurements have been used to probe the microscopic water distribution in a variety of starch-based systems, including packed beds of native starch granules with varying water contents, starch gels, and freeze-dried starch gels. The q-space data for the granular beds is compared with a variety of theoretical models and conforms best to unbounded diffusion in a lower dimensional space. In contrast to some earlier reports, the data for the gelatinized samples are not anomalous and conform to simple unrestricted diffusion in a three-dimensional space. The paper concludes with a novel method for probing pore size distribution in freeze-dried starch gels by infusion of acetone.

A new concept for implementation of a required general surgery clerkship

BACKGROUND

Two years ago our institution abbreviated the junior internal medicine and general surgery clerkships to accommodate a 4-week family practice clerkship and a 4-week elective clerkship. As a consequence, 1-month mandatory internal medicine and general surgery clerkships were placed in the senior year.

METHODS

The surgical disorders most commonly encountered by the generalist are discussed. The senior students spend 4 weeks with a community-based surgeon. All lectures are presented by full-time faculty and adhere to the student manual, which is designed to coincide with examination material. Three histories and physicals are reviewed by the course director to determine utilization of critical thinking skills. The development of healthy interpersonal and professional relationships is addressed by a 2-hour module on the essentials of integrity, compassion, humility, and self-knowledge. A faculty development seminar provides an awareness of course objectives and logistics. Student grades are determined by the preceptor's evaluation (50%), an in-house written examination (50%), and submission of adequate history and physicals.

RESULTS

Subjective reviews by students (n = 115) reveal that although only 27% of the students care to pursue a surgical practice, 85% feel that their time was effectively spent and 83% feel that the clerkship should be offered to future fourth year medical students. Seventy percent of submitted history and physicals (n = 420) exhibit appropriate critical thinking skills.

CONCLUSIONS

We are currently in the midst of our third year of implementation. The students are receiving insight into a surgical approach to common disease processes. History and physical examination skills and healthy interpersonal relationships are reinforced. Although change is often difficult to accomplish and accept, the positive response to the newly formatted senior curriculum has exceeded expectations.

Post-traumatic stress disorder symptoms among Gulf War veterans

This study assessed the prevalence of risk for development of post-traumatic stress disorder (PTSD) symptoms among active duty and reserve veterans from Pennsylvania and Hawaii who either deployed (N = 1,524) or did not deploy (N = 2,727) to the Persian Gulf as a result of Operation Desert Storm. All participants anonymously completed a survey questionnaire that included the Impact of Event Scale and the Brief Symptom Inventory. Results indicate the likelihood of PTSD symptoms in approximately 8.0% of active duty veterans and 9.3% of reserve veterans who deployed to the Persian Gulf. PTSD risk comparisons are made with other active duty Army veterans assessed 1 year earlier. Sources of trauma are presented and implications for future military deployments on potential risks for developing PTSD are discussed.

Psychological health of Gulf War-era military personnel

This study assessed the effects of the Persian Gulf War on the psychological health and adjustment of military personnel in Hawaii and Pennsylvania who either deployed (N = 1,524) or did not deploy (N = 2,727) to the Persian Gulf during Operations Desert Shield/Desert Storm. All participants anonymously completed a questionnaire providing information on demographics, psychological and psychosocial health, deployment stressors, current life problems, current distress, and causal attributions of present problems. Results indicate that deployed veterans experienced significant levels of stress in-theater and continue to report significant stress in their lives today. Although considerable stress is experienced, the majority of veterans are handling it unremarkably. Implications for future deployments and the need for military-normed assessment instruments are discussed.

Dynamic NMR Q-space studies of microstructure with the multigrade CPMG sequence

A new approach to q-space studies of microstructure is proposed, which exploits the combined information contained in the water proton transverse relaxation time distribution and the frequency dependence of the apparent water diffusivity in heterogeneous systems. Using an automated two-dimensional multigrade CPMG sequence, both the pulse spacing and the amplitude of the applied field gradient are varied systematically and used to measure the frequency and wave vector dependence of the multiple exponential echo decay constants and amplitudes. Undesirable crossterms in the applied and background field gradients are eliminated by a simple procedure involving a sign reversal in the applied gradient. Nonlinear, local susceptibility-induced field gradients are shown to lead to enhanced, frequency-dependent apparent water diffusivities that are sensitive to the local microstructure.

Combined relaxation and diffusion studies of porous media using the multigrade CPMG sequence

A new approach to q-space NMR studies of microstructure is proposed that exploits the combined information contained in the water proton transverse relaxation time distribution and the frequency dependence of the apparent water diffusivity. A simple protocol is used to eliminate undesirable crossterms in background susceptibility gradients. Local, microscopic nonlinearity in the applied field gradients is shown to lead to enhancement of the apparent water diffusivity in small pores at high frequencies. The relationships between NMR relaxation studies of pore emptying with sorption isotherms, electrical conductivity, and microbiological survival are indicated.

Quality of life and functional status among homeless men attending a day shelter in Louisville, Kentucky

The homeless present important social and medical problems in most parts of the United States, including urban areas of Kentucky. While some studies have examined the health status of the homeless, very little is known about their quality of life or functional status. In the present study, 188 homeless men attending St. John's Day Shelter in Louisville completed an interviewer-assisted instrument that assessed self-perceived quality of life using the Perceived Quality of Life (PQOL) scale and self-perceived functional status using the Dartmouth COOP charts. The instrument also included questions on demographics and health risk behaviors of the homeless men. The results show that the typical homeless male attending St. John's is an unmarried, white, middle-aged high school graduate who is unemployed. In terms of quality of life, these men indicate general satisfaction with their physical and cognitive abilities, but significantly lower satisfaction with the social aspects of their lives. With regard to functional status, the homeless men report that they function best in terms of physical fitness and ability to perform daily activities. They report lower assessments of overall health, feelings, quality of life, and social support. These results suggest that poor social role functioning among homeless men is a major contributor to their poor quality of life. Thus, improving their health and quality of life may require an emphasis on social services in addition to routine medical care.

Gruesomeness, emotional attachment, and personal threat: dimensions of the anticipated stress of body recovery

Previous research has shown that exposure to grotesque death has been associated with posttraumatic stress disorder and higher levels of stress have been associated with mortuary workers who anticipated handling remains than those who did not. Additional research is presented here to further clarify the nature of the anticipated stress of handling the dead. Anticipated stress of handling human remains was rated for 13 different situations by 479 persons (384 men and 95 women) without such experience, but whose job was likely to require it. Factor analysis of their ratings revealed three psychological dimensions: the gruesomeness of the remains, an emotional link between the viewer and the remains, and personal threats to the remains handler. Suggestions for preventive measures, training, and interventions for those who may handle remains are made.

Physical health symptomatology of Gulf War-era service personnel from the states of Pennsylvania and Hawaii

We present data on physical health and possible "Gulf War syndrome" from a Congressionally mandated study of over 4,000 active duty and reserve service members from the states of Hawaii and Pennsylvania who served during Operation Desert Storm. We found that deployed veterans report significantly more physical health symptoms than non-deployed veterans that cannot be explained by reasons other than deployment alone. We also identified a subgroup of 178 deployed veterans at risk for possible Gulf War syndrome. We recommend that services collect baseline information from units likely to deploy in the future and update that information regularly.

A new model for bacterial growth in heterogeneous systems

A general theory of spatially dependent bacterial growth in heterogeneous systems is developed by combining a structured-cell kinetic model of bacterial metabolism with reaction-diffusion equations describing the transport of nutrients in the growth medium. Rate constants in the theory are determined for Listeria monocytogenes by fitting the viable count batch growth data acquired in homogeneous, shake-flask cultures. The rate constants are then used to calculate the form of bacterial growth when it occurs as localized microcolonies in structured systems. The same theory is used to analyse the effects of transient variations in environmental variables.

An MRI study of drying in granular beds of nonporous particles

MRI is used to study the role of capillary and gravitational forces in controlling mass transport of water during isothermal drying of granular beds of nonporous particles. A new model is presented that shows how capillary and gravitational forces relate to Fickian diffusion driven by a chemical potential gradient. In granular beds, where capillary and gravitational forces dominate, the image profiles give direct information on the dependence of the degree of saturation on capillary suction pressure. The effects of changing particle size and surface tension on the profiles is investigated quantitatively, and it is shown that high capillary pressures create anomalies in the drying profiles.

Anticipation of handling the dead: effects of gender and experience

In addition to the direct psychological effects of disaster stressors, anticipation of stress can itself be debilitating. We examined the relationship between the anticipated stress of handling the dead and gender and experience. Experienced persons had lower anticipated stress than inexperienced persons. Inexperienced, females had higher anticipated stress than inexperienced males; experienced males and females did not differ. Results provide support for an 'inoculation' theory of stress buffering in disaster workers.

Handling bodies after violent death: strategies for coping

Interviews with and observations of experienced and inexperienced personnel were conducted to determine their coping strategies before, during, and after their work with the bodies of people who had died violently. Avoidance, denial, and social support from the work group and spouse appeared to facilitate coping. The implications of these findings for therapeutic intervention are discussed.

Effect of sink isolation on sugar uptake and starch synthesis by potato-tuber storage parenchyma

Import into potato (Solarium tuberosum L. cv. Record) tubers was terminated by removing the sink at its connection with the stolon. The ability of discs of storage tissue from the excised tubers to take up exogenous sugars and convert them to starch was compared with that of discs from untreated tubers from the same plant population. In rapidly-growing control tubers, glucose and fructose were taken up to a greater extent than sucrose, 77% of the glucose being converted to starch within 3 h (compared with 64% and 27% for fructose and sucrose, respectively). These values fell as the tubers aged but the ranking (glucose > fructose > sucrose) was maintained, emphasising a severe rate-limiting step following the import of sucrose into the growing tuber. Sink isolation had little effect on the ability of the storage cells to take up exogenous sucrose across the plasmalemma for up to 7 d after sink isolation. However, the ability of the same cells to convert the sucrose to starch was severely inhibited within 24 h, as was the sensitivity of starch synthesis to turgor. In the case of glucose, sink isolation inhibited both the uptake and the conversion to starch, the latter being inhibited to a greater degree. A detailed metabolic study of tubers 7 d after excision showed that, with sucrose as substrate, 94% of the radioactivity in the soluble sugar pool was recovered in sucrose following sink isolation (92% in control tubers). However, with glucose as substrate, 80% of the radioactivity was recovered as sucrose following tuber excision (28% in control tubers), providing evidence that sucrose synthesis acts as a major alternative carbon sink when starch synthesis is inhibited. In the same tubers, sucrose-synthase activity decreased by 70% following sink isolation, compared with a 45% reduction in ADP-glucose pyrophosphorylase. Activities of UDP-glucose pyrophosphorylase, starch phosphorylase, starch synthase nd both PPi- and ATP-dependent phosphofructokinases remained unchanged. Acid-invertase activity increased fivefold.

The effects of restricted diffusion in nuclear magnetic resonance microscopy

A stochastic computer simulation is used to investigate the effects of restricted diffusion in NMR microscopy. It is shown that diffusion contributes to a loss of interfacial resolution through two main mechanisms. The first applies to spatial regions bound by impermeable interfaces and involves diffusive averaging of the frequency differences set up by the applied field gradients. This effect can be made arbitrarily small by increasing the magnitude of the field gradient. The second mechanism involves diffusion through permeable membranes or interfaces defining the sample morphology. This effect can, in principle, be reduced by multiple echo imaging with short pulse spacings. The possibility of imaging diffusive flow through a permeable interface is discussed.

The shared experience of catastrophe: an expanded classification of the disaster community

Based on observational and interview data following a major air crash, a classification of individuals affected by catastrophe is proposed in which degree of involvement is used to characterize the dynamic nature of the disaster community. The model encompasses individual and group activities, roles and relationships, and the shared meaning of the traumatic event. Implications for the identification of neglected participants and for preventive community intervention are offered.

Uptake of Lucifer Yellow CH into plant-cell protoplasts: a quantitative assessment of fluid-phase endocytosis

The highly fluorescent dye Lucifer Yellow CH (LYCH), now in common use in microinjection studies, has been shown to enter the vacuole of a range of plant-cell protoplasts from the external medium. Uptake was quantified by lysing the protoplasts following incubation and determining the amount of LYCH incorporated by spectrofluorimetry. Uptake was biphasic with respect to both time and substrate concentration, enhanced at low pH and inhibited by low temperature and metabolic inhibitors. The kinetics of uptake showed several similarities with those reported for the fluid-phase endocytosis of LYCH in animal cells and yeast cells. A calculated membrane permeability coefficient for LYCH, based on the observed rates of uptake, was too high to be consistent with simple diffusion of the undissociated form of the molecule and inconsistent with the membrane-impermeant properties of the dye. The data are discussed in the light of the possibility of fluid-phase endocytosis versus active transmembrane transport.

The impact of a military air disaster on the health of assistance workers. A prospective study

The worst peacetime disaster in United States Army history occurred on December 12, 1985 in Gander, Newfoundland. A charter airline carrying 248 soldiers home from peacekeeping duties in the Sinai Desert crashed after a refueling stop, killing all on board. After the crash, Army family assistance workers were appointed to help the surviving family members of each dead soldier. While substantial attention has been paid to the impact of sudden disasters on survivors and bereaved relatives, little is known about the health risks to those who perform helper roles. This study aimed to: a) identify the major stress areas for disaster family assistance workers; b) examine the relation between degree of exposure to these stressors and health; and c) locate risk factors, or resistance resources that might modulate any ill effects of exposure. A survey instrument assessed duration and intensity of family-helping activities and psychological well-being, psychiatric symptoms, major illness indicators, and social and personality variables at 6 months after the crash and again at the 1-year point for 131 family assistance officers. Results indicate a dose-response effect between exposure measured at time 1 and well-being, symptoms, and illness at time 2. Analysis of covariance findings also show that social supports (work supervisors, family, and friends) modulate the effects of exposure on symptoms and well-being. Social supports and the personality style of hardiness (or dispositional resilience) interact to modulate the effects of exposure on illness. These results demonstrate: a) a delayed negative impact of helper stress on family assistance workers, and b) a protective function of social supports and personality hardiness. Further research in this area should thus consider the potential influence of social/situational variables and personality dispositions in coping with disaster helper stress.

Sucrose uptake and partitioning in discs derived from source versus sink potato tubers

The uptake of sucrose into isolated discs cut from sink (growing) and source (sprouting) potato (Solanum tuberosum L.) tuber tissue was studied. The uptake of sucrose into sink-tuber discs demonstrated biphasic kinetics. The large saturable component was inhibited by incubation of the discs with p-chloromercuribenzene sulfonic acid (PCMBS) whilst both the saturable and linear components were inhibited by carbonyl cyanide m-chlorophenylhydrazone (CCCP). By contrast, in source-tuber discs, the linear component represented the majority of sucrose taken up, the saturable component playing only a minor role. In source discs, only the saturable component of uptake was inhibited by either PCMBS or CCCP. A large proportion (up to 25%) of sucrose taken up into sink-tuber discs was converted to starch but as the tubers aged the proportion of sucrose converted to starch decreased to the level found in source-tuber discs (approx. 3%). By contrast with sink-tuber discs (see Oparka and Wright, 1988b, Planta 175, 520-526) sucrose uptake into source discs was insensitive to turgor and demonstrated an uptake pattern similar to that of CCCP-treated sink tissue. It is proposed that exogenous sucrose is taken into the storage parenchyma of sink-tuber discs by both a carrier-mediated and a diffusional process. By contrast, uptake into the storage parenchyma of source-tuber discs appears to be essentially diffusional. The turgor sensitivity of sucrose uptake into sink-tissue discs may be mediated via the plasmalemma H(+)-ATPase. As the tuber ages the sucrose-uptake activity decreases and the capacity of the storage parenchyma to synthesise starch is lost. The data are discussed in relation to the in-vivo mechanisms of sucrose transport in storage tissues.

Uptake of Lucifer Yellow CH into intact barley roots: Evidence for fluid-phase endocytosis

Intact barley (Hordeum vulgare L.) roots have been shown to take up the highly fluorescent dye Lucifer Yellow CH (LYCH) into their cell vacuoles. In the apical 1 cm of root tip, differentiating and dividing cells showed a prolific uptake of LYCH into their provacuoles. The LYCH was retained during fixation, apparently becoming bound to electron-dense material in the vacuoles. The dye freely entered the apoplast of roots in which the Casparian band was not developed, being taken up into the vacuoles of cells in both the cortex and stele. However, when LYCH was applied to a 1-cm zone approx. 6 cm behind the root tip the Casparian band on the radial walls of the endodermis completely prevented the dye from entering the cells of the stele, only the cell walls and vacuoles of the cortical cells taking up the dye. The inability of LYCH to cross the plasmalemma of the endodermal cells and enter the stele via the symplast substantiates previous claims that the dye is unable to cross the plasmalemma of plant cells. The results are discussed in the light of recent demonstrations that LYCH is a particularly effective marker for fluid-phase endocytosis in animal and yeast cells. A calculation of the energetic requirements for LYCH uptake into barley roots supports the contention that LYCH is taken up into the vacuoles of plant cells by fluid-phase endocytosis.

Influence of cell turgor on sucrose partitioning in potato tuber storage tissues

Sucrose uptake and partitioning in potato (Solanum tuberosum L.) tuber discs were examined under a range of mannitol and ethylene-glycol concentrations. Mannitol caused the same changes in turgor over a wide range of incubation periods (90 min-6 h), indicating that it did not penetrate the tissue. In comparison, ethylene glycol reduced turgor losses but did not eliminate them, even after 6 h. Between 100 mM and 300 mM mannitol, turgor fell by 350 kPa, compared with 35 kPa in ethylene glycol. Uptake experiments in mannitol alone showed that total sucrose uptake was strongly correlated with both osmotic potential and with turgor potential. In subsequent experiments sucrose uptake and partitioning were examined after 3 h equilibration in 100 mM and 300 mM concentrations of mannitol and ethylene glycol. Total sucrose uptake and the conversion of sucrose to starch were enhanced greatly only at 300 mM mannitol, indicating an effect of turgor, rather than osmotic potential on sucrose partitioning. The inhibitors p-chloromercuribenzenesulfonic acid and carbonylcyanide m-chlorophenylhydrazone (CCCP) both reduced sucrose uptake, but in quite different ways. p-Chloromercuribenzenesulfonic acid reduced total sucrose uptake but did not affect the partitioning of sucrose to starch. By contrast, CCCP inhibited total uptake and virtually eliminated the conversion of sucrose to starch. Despite this, sucrose uptake in the presence of CCCP continued to increase as the mannitol concentration increased, indicating an increase in passive transport at higher mannitol concentrations. Increased sucrose uptake above 400 mM mannitol was shown to be the result of uptake into the free space. The data show that starch synthesis is optimised at low but positive turgors and the relation between sucrose partitioning and the changing diurnal water relations of the tuber are discussed.

Osmotic regulation of starch synthesis in potato tubers?

Using potato (Solanum tuberosum L.) tuber discs incubated in a range of mannitol concentrations it has been demonstrated that both sucrose uptake and the conversion of sucrose to starch are sensitive to the osmotic environment of the storage cells. Starch synthesis was optimised at 300 mM but declined sharply at both lower and higher osmotic concentrations. The decline in starch synthesis on either side of optimum was not proportional to the change in mannitol concentration, indicating different inhibitory mechanisms under low and high osmotica. The fraction of the total sucrose converted to starch i.e. the partitioning between sucrose and starch, was also influenced by osmotic environment. The amount of soluble material taken up by the storage cells, but not converted to starch, was maintained under mannitol concentrations (300-400 mM) which inhibited starch synthesis, indicating that sucrose uptake continued during declining starch synthesis. At mannitol concentrations above 400 mM, sucrose uptake was greatly enhanced but no significant change in starch synthesis occurred.

Awareness training in the treatment of head and facial tics

The effectiveness of awareness training alone in treating multiple tics in a young adult was assessed using a multiple baseline across behaviors design. The results showed that the awareness training was very effective in suppressing both head and facial tics and that the treatment effects generalized to a nonclinic situation. Follow-up data showed that both tics were still at low levels one, two, four and eight months after treatment. Treatment satisfaction ratings by the subject and social validation ratings by independent observers are also reported.