Are Small GTPases Signal Hubs in Sugar-Mediated Induction of Fructan Biosynthesis?

External sugar initiates biosynthesis of the reserve carbohydrate fructan, but the molecular processes mediating this response remain obscure. Previously it was shown that a phosphatase and a general kinase inhibitor hamper fructan accumulation. We use various phosphorylation inhibitors both in barley and in Arabidopsis and show that the expression of fructan biosynthetic genes is dependent on PP2A and different kinases such as Tyr-kinases and PI3-kinases. To further characterize the phosphorylation events involved, comprehensive analysis of kinase activities in the cell was performed using a PepChip, an array of >1000 kinase consensus substrate peptide substrates spotted on a chip. Comparison of kinase activities in sugar-stimulated and mock(sorbitol)-treated Arabidopsis demonstrates the altered phosphorylation of many consensus substrates and documents the differences in plant kinase activity upon sucrose feeding. The different phosphorylation profiles obtained are consistent with sugar-mediated alterations in Tyr phosphorylation, cell cycling, and phosphoinositide signaling, and indicate cytoskeletal rearrangements. The results lead us to infer a central role for small GTPases in sugar signaling.     

Conceptual issues specifically related to health-related quality of life in critically ill patients

During recent years increasing attention has been given to the quality of survival in critical care. Health-related quality of life (HRQOL) is an important issue both for patients and their families. Furthermore, admission to the intensive care unit can have adverse psychological effects in critically ill patients. Recent studies conducted in critically ill patients have measured HRQOL. However, usually absent from such reports are evaluations of conceptual issues, addressing factors such as why HRQOL should be measured in critically ill patients, how to define and standardize domains of HRQOL, whether proxies can provide useful information about HRQOL in critically ill patients, whether response shift occurs in critically ill patients, and whether post-traumatic stress disorder (PTSD) occurs in critically ill patients. Some studies reported moderate agreement between patients and their proxies, although lower levels of agreement may be reported for psychosocial or physical functioning. Response shift (adaptation and change in perception) appears to be an important phenomenon and likely to be present, but it is seldom measured when estimating HRQOL in critically ill patients. Furthermore, vigilance for symptoms of PTSD and early interventions to prevent PTSD are needed.     

Pathway analysis of gene signatures predicting metastasis of node-negative primary breast cancer

Background  

Published prognostic gene signatures in breast cancer have few genes in common. Here we provide a rationale for this observation by studying the prognostic power and the underlying biological pathways of different gene signatures.     

Maternal HIV infection, drug use, and growth of uninfected children in their first 3 years

OBJECTIVE: To determine the separate effects of maternal HIV infection and drug use during pregnancy on growth of uninfected children in their first 3 years. DESIGN: Retrospective analysis of measurements from health visitor records made during routine child health surveillance at 6 weeks, 10 months, and 3 years of age. Multilevel analysis allowed for between-infant variation in fitted growth lines, and adjustment for other factors. Growth was described in terms of an intercept (z score at term) and growth slopes (change in z score per year) up to, and from, 4 months. SUBJECTS: 290 case babies delivered in Edinburgh hospitals to women who reported injection drug use by either themselves or their HIV infected partner, and 186 community controls. A total of 131 (45%) of the case babies were born to women who used drugs, predominantly opiates, during pregnancy and 93 (32%) to HIV infected women. The eight infected children were excluded from analysis. MAIN OUTCOME MEASURES: Age and sex standardised z scores for height, weight, and body mass index. RESULTS: 459 (96%) of the 476 records for cases and controls were traced, yielding 1432 weight and 939 height measurements. Maternal HIV infection was not found to affect growth; at 3 years the estimated effect on weight z score was 0.16 with 95% confidence interval (-0.25 to 0.57) and for height 0.18 (-0.19 to 0.55). Drug use during pregnancy was associated with lighter babies at 40 weeks followed by depressed growth in the first four months, these infants remaining just slightly smaller at 3 years with an estimated effect on z scores of -0.5 for weight with 95% confidence interval (-0.89 to -0.11) and -0.37 (-0.72 to -0.02) for height. CONCLUSIONS: Maternal HIV infection does not adversely affect growth in uninfected infants, and the effect of drug use during pregnancy is limited to small decrease in size at 3 years.     

The association between nutritional status and handgrip strength in older Rwandan refugees

OBJECTIVES: To investigate the association between nutritional status and handgrip strength in older Rwandan refugees. DESIGN: Cross-sectional study. SETTING: Rwandan refugee camp located in Karagwe district in the north-west of Tanzania. The study was carried out in the post-emergency phase. The response rate was 85%. SUBJECTS: A total of 413 men and 415 women aged 50-92 y participated in the study. METHODS: Weight, height, mid-upper-arm circumference (MUAC) and triceps skinfold were obtained using standard techniques. For people with visible kyphosis, height was estimated from armspan using regression equations developed from non-kyphotic subjects within the sample. Handgrip was measured using a mechanical handgrip dynamometer. Information regarding physical activity and health status was obtained by interview and clinical screening. RESULTS: Handgrip strength (kg) was significantly higher in men than in women (30.3+/-6.7 vs 22.3+/-5.1), and significantly lower in each older age group in both sexes. Handgrip strength was positively correlated to BMI (body mass index) and AMA (arm muscle area). The relative risk of impaired handgrip strength in individuals with poor nutritional status (BMI<18.5 kg/m(2)) compared with those of adequate nutritional status was 1.75. After controlling for potential confounders (sex, age and height), BMI remained a significant contributor to the variation in handgrip strength. CONCLUSION: Poor nutritional status is associated with poor handgrip strength independent of sex, age and height, in this refugee population. This may indicate that underweight older people are likely to have more difficulties in functioning independently in the community. Research is needed to investigate if improving nutritional status can lead to better functional ability. SPONSORSHIP: Department for International Development (UK) and HelpAge International.     

Sarcomatoid renal cell carcinoma: Rapid dissemination detected on FDG PET‐CT

We present the FDG PET‐CT findings in a patient with persistent pain 7 weeks after a nephrectomy and lymph node dissection for a sarcomatoid renal cell carcinoma. Although conventional imaging was unable to detect evidence of metastatic spread outside the para‐aortic nodes, a PET‐CT scan showed unexpected extensive dissemination. Currently, there are no reports in the literature of the PET‐CT findings in sarcomatoid renal cell carcinomas.     

Initiating activity of the anti-estrogen tamoxifen, but not toremifene in rat liver

A striking difference between two structurally related anti-estrogen medicines is that tamoxifen is strongly hepatocarcinogenic in the rat, whereas toremifene lacks such activity. To study the basis for this difference, the initiating potential of tamoxifen and toremifene were studied by measurement of rapid induction of hepatocellular altered foci (HAF) that express placental-type glutathione S-transferase in the livers of female Sprague-Dawley (S-D) rats and female Fischer 344 (F344) rats. Both agents were administered by gavage at equimolar doses up to a dose that produced marked weight gain suppression. In rats given the high dose of 40 mg/kg per day tamoxifen continuously for 36 weeks, 75% of S-D rats developed liver neoplasms, in contrast to only 10% of F344 rats. In the S-D strain, tamoxifen produced a tendency to increased HAF at 2 weeks at the dose of 40 mg/kg per day and by 12 weeks, a dose-related increase was evident. In contrast, toremifene induced no HAF even at the equimolar high dose of 42.4 mg/kg per day for 12 weeks. The induction of HAF by tamoxifen was less in the F344 rats. Neither agent elicited increases in hepatocellular proliferation in S-D or F344 rats. When phenobarbital was administered for 24 weeks as a promoting agent after the anti-estrogens, S-D rats given tamoxifen at 20 mg/kg per day for 12 weeks, developed liver neoplasms, but not F344 rats or rats of either strain given even a higher dose (42.4 mg/kg) of toremifene. Thus, tamoxifen has initiating activity in these rat strains whereas toremifene does not.      

Myelin thickenings in val 102/fs null mutation of MPZ gene

Painful sensory neuropathies consist of a wide range of neuropathies that can involve large as well as small nerve fibres. Even if most cases remain of unknown cause, some of them may be associated with an underlying disorder such as diabetes, HIV, infections, amyloidosis, and Sjogren's syndrome. Since in some cases an autoimmune mechanism has been postulated, we investigated a panel of circulating autoantibodies including anti‐gliadin (AGA), anti‐endomysium (EmA), anti‐transglutaminase (tTGA) and anti‐nuclear (ANA) antibodies in the sera of patients with unexplained painful sensory neuropathies in order to identify other potentially treatable disorders. We tested the sera of 10 patients (4M; 6F) previously investigated for other causes of neuropathies, including anti‐nerve, onconeural, anti‐extractable nuclear, anti‐neutrophil cytoplasmic, anti‐thyroglobulin (TgA) and anti‐peroxidase (TPOA) antibodies. We found the presence of AGA positivity in 4 patients (40%), ANA in 7 (70%) and AGA + ANA in 4 (40%), two of whom were negative for celiac disease by gastrointestinal biopsy. None of the patients had EmA positivity. Three (30%) had TgA and TPOA and none had anti‐nerve or onconeural antibodies. Whether the presence of circulating autoantibodies in patients with unexplained painful neuropathy reflects an autoimmune involvement which may be amenable to immune therapy and not only to symptomatic treatment remains to be established.