Fatty acid synthetase activity in Mycobacterium phlei: regulation by polysaccharides

The multienzyme complex from Mycobacterium phlei which catalyzes the synthesis of long chain fatty acids from acetyl-CoA and malonyl-CoA requires a heat-stable fraction (stimulating factor, SF) for activity. Fractionation of heat-treated M. phlei extracts affords two stimulatory subfractions, one of which (SF(2)) can be replaced by FMN. The other (SF(1)) is further separable into 3 polysaccharides (PS(I), PS(II), and PS(III)). PS(I) contains about 95% 3-O-methylmannose and 5% mannose; the sugar composition of PS(II) and PS(III) is about 55% 6-O-methylglucose and 45% glucose for both. Each of the three purified polysaccharides, in combination with FMN, substitutes for the crude stimulating factor. The polysaccharides exert their effect on the fatty acid synthetase by lowering the K(m) for acetyl-CoA about 50-fold.

Measurement of leisure time satisfaction in family caregivers

Caregiving is known to limit participation in a variety of roles. Leisure roles are increasingly recognized as important for the well-being of older adults. Little is known, however, about the impact of caregiving on leisure activities, and existing measures are of limited utility in caregiving research. We developed the Leisure Time Satisfaction (LTS) measure to allow further study of the impact of caregiving on caregivers' leisure time satisfaction, the role of leisure in understanding the caregiving process, and whether caregiving interventions improve leisure time satisfaction. The six-item LTS measure shows excellent psychometric properties, including internal consistency, a single factor structure, and convergent validity. Psychometric features are robust across diverse groups of caregivers, including subgroups varying by race/ethnicity and relationship to the care recipient. The LTS measure appears to be a promising tool for inclusion in caregiving research.

Modulation of a cloned mouse brain potassium channel

The mouse brain K+ channel (MBK), previously cloned by others, has been independently cloned and shown to express in Xenopus oocytes. This K+ current (IK) inactivated over a time course of seconds and was sensitive to the K+ channel-blocking reagent tetraethylammonium. When the K+ channel was coexpressed with a cloned mouse brain serotonin receptor (5HT1c) in oocytes, activation of the 5HT1c receptor by a brief application of serotonin resulted in a suppression of the IK amplitude over the next 20 min. IK could also be suppressed by activation of G proteins. Suppression was also caused by intracellular Ca2+ injections and was blocked by intracellular injection of EGTA. Calmodulin antagonists block the IK suppression, but a known protein kinase inhibitor did not block suppression. The 5HT1c suppression was reversible; recovery from suppression was blocked by the protein kinase inhibitor H-7. These data suggest that the IK suppression occurs through a novel mechanism independent of A- or C-type protein kinases; suppression is best explained as being due to the action of a Ca2+/calmodulin-activated phosphatase; recovery from suppression is due to the action of a protein kinase.

Parenting, autonomy and self-care of adolescents with Type 1 diabetes

BACKGROUND

During adolescence diabetes creates a juncture of very complex disease management demands with developmental needs, including the striving of adolescents for greater autonomy. Parents' concerns and fears about the teen's diabetes self-management abilities during this time can heighten parental attachment behaviour and affect the parents' ability to support autonomy development necessary for effective self-care. Maternal parenting processes may be especially important for those adolescents who have Type 1 diabetes because mothers are the primary caregivers.

PURPOSE

Based on attachment theory, the aim was to test a model of the influence of mother-adolescent developmental conflict, maternal separation anxiety and maternal inhibition of autonomy and relatedness on cognitive autonomy and self-care of adolescents with Type 1 diabetes.

METHOD

A total of 131 families with an adolescent, aged 11-15 years, contributed data annually across three waves. Mothers and adolescents completed paper-and-pencil measures and two interaction scenarios that were coded by trained staff from audio-tapes. The adolescent also completed a structured interview and questionnaire to assess self-care.

RESULTS

Maternal separation anxiety when adolescents were 11-15 years of age directly predicted cognitive autonomy at 1-year follow-up, and that cognitive autonomy was directly related to self-care 1 year later, but did not mediate between separation anxiety and self-care.

CONCLUSIONS

Future investigation of the influence of separation anxiety of parents on adolescent autonomy development is warranted, as well as the contribution of autonomy development to diabetes self-management behaviours of adolescents.

Isotopic constraints on the evolution of metamorphic conditions in the Jijal-Patan complex and the Kamila Belt of the Kohistan arc, Pakistan Himalaya

Pressure-temperature data and Sm-Nd and Rb-Sr garnet ages are presented for retrogressed granulitic rocks of the Jijal-Patan complex and the Kamila Amphibolite Belt. Despite the retrogression and hydration, the two samples contain garnet and hydrous minerals that yield pressures and temperatures similar to previous estimates for pristine granulite facies rocks from the same area. The Sm-Nd and Rb-Sr garnet ages are concordant at 95–100 Ma for the two samples and for both isotopic systems. These ages are interpreted as dating cooling through 700–800 °C following magmatic crystallization and granulite facies metamorphism. In the case of the garnet amphibolites from the Kamila Belt, the garnets retain prograde major element zonation. In addition, the closure temperature for the Rb-Sr system is very close to the recorded temperature. For these reasons, the age of 100 Ma must represent a time close to that when the pressure and temperature preserved in the mineralogy and its chemistry was recorded. The isotopic equilibrium between garnet and paragonite at 90–100 Ma suggests that the regional hydration event that affected the lower crust of the Kohistan arc also occurred at this time. Cooling rates calculated from the Rb-Sr and Sm-Nd ages for the partially retrogressed granulite give a minimum of 3–6°C Ma−1 and imply a different tectonic mechanism for the exhumation of the lower crust than is typical for granulites. This process may be related to early regional decompression following the collision of the Kohistan arc with Eurasia.

Considering olfactory stimulation for adults with age-related dementia

Behavioral interventions and activities for adults with age-related dementias sometimes use olfactory stimulation; however, limitations to the usefulness of such stimulation are suggested by both neurological studies which show a large amount of degeneration in the cells of the olfactory bulb and studies of perception which indicate that adults with Alzheimer's disease and related dementias perform poorly on tests of smell identification and detection. Current approaches to using olfactory stimulation as a component of interventions for adults with age-related dementia may need to be either abandoned or reassessed.

Barriers to use of services by older homeless people

Analysis of responses during participant observation and face-to-face interviews of four homeless elders and six service providers indicated that the four elders comprehended and used the service environment; however, hopelessness (learned helplessness) appears to be the largest personal obstacle to use of such resources by elderly homeless persons to change their situation.

Rest tremor associated with exposure to Monensin

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Barriers and aids in conducting research with older homeless individuals

Field notes of a qualitative pilot study of older homeless people in Cincinnati identified several barriers and aids to the study of homeless elders. Identified research barriers were researcher's lack of contextual wisdom (street smarts), locating elders, substance abuse, attrition, victimization, credibility of informants, and xenophobia. Identified research aids were friendliness of certain elders, openness of the researcher, attractive incentives in exchange for interviews, and service providers' willingness to share experiences.

Traits of volunteers preferred by older adults

Face-to-face interviews of 46 people 60 years or older indicated that promptness, friendliness, and kindness were attributes desirable in those who volunteer to perform services for older people.