Transdermal Nicotine Treatment and Progression of Early Parkinson's Disease

Nicotine Treatment and Parkinson's DiseaseIn this randomized, controlled trial, patients with Parkinson's disease not on dopaminergic therapy were randomly assigned to receive transdermal nicotine or placebo. After 1 year, there was no difference in the change in Total Unified Parkinson's Disease Rating Scale score between groups.

[An older patient with depression, anxiety and acute amnesia]

We saw a 73-year-old woman, diagnosed with a recurrent depression and generalized anxiety disorder. Escitalopram had been started by her general practitioner more than seven weeks ago. It was not effective, and was therefore tapered with the aim of starting a different antidepressant. During tapering acute memory problems occurred, presumed to be atypical transient global amnesia. Here we highlight the psychiatric, pharmacological and neurological considerations and differential diagnosis of acute memory disorders.

[Pilot study of psychiatric and social aspects of children and adolescents with fragile X syndrome]

Objective

The study describes the burden of psychosocial risks of mental illnesses and the ways in which children and adolescents with fragile X syndrome (FRX) can be treated.

Method

Data from a sample of 34 patients with FRX younger than 18 years stemming from a prospective multicenter (n = 11) registry study (EXPLAIN) were analyzed with regard to psychosocial burden and Treatment.

Results

One third of all participants reported having relatives who suffer from FRX. The majority of participants were suffering themselves from one kind or another mental or neurological problems. Younger participants (< 14 years) tended to suffer from atactic disorders, epileptic seizures, and autistic symptoms. These disorders were usually treated by psychotropic drugs supplemented by logopedic therapies and occupational therapies (more than once a month). In our sample, 96.3 % of the younger patients and more than 57.1 % of the older patients were still living with their parents.

Conclusions

Patients with FRX often suffer from additional neurological and mental disorders. For that reason, they should be diagnosed and treated early on.

Mavoglurant in fragile X syndrome: Results of two randomized, double-blind, placebo-controlled trials

Fragile X syndrome (FXS), the most common cause of inherited intellectual disability and autistic spectrum disorder, is typically caused by transcriptional silencing of the X-linked FMR1 gene. Work in animal models has described altered synaptic plasticity, a result of the up-regulation of metabotropic glutamate receptor 5 (mGluR5)-mediated signaling, as a putative downstream effect. Post hoc analysis of a randomized, placebo-controlled, crossover phase 2 trial suggested that the selective mGluR5 antagonist mavoglurant improved behavioral symptoms in FXS patients with completely methylated FMR1 genes. We present the results of two phase 2b, multicenter, randomized, double-blind, placebo-controlled, parallel-group studies of mavoglurant in FXS, designed to confirm this result in adults (n = 175, aged 18 to 45 years) and adolescents (n = 139, aged 12 to 17 years). In both trials, participants were stratified by methylation status and randomized to receive mavoglurant (25, 50, or 100 mg twice daily) or placebo over 12 weeks. Neither of the studies achieved the primary efficacy end point of improvement on behavioral symptoms measured by the Aberrant Behavior Checklist-Community Edition using the FXS-specific algorithm (ABC-C(FX)) after 12 weeks of treatment with mavoglurant. The safety and tolerability profile of mavoglurant was as previously described, with few adverse events. Therefore, under the conditions of our study, we could not confirm the mGluR theory of FXS nor the ability of the methylation state of the FMR1 promoter to predict mavoglurant efficacy. Preclinical results suggest that future clinical trials might profitably explore initiating treatment in a younger population with longer treatment duration and longer placebo run-ins and identifying new markers to better assess behavioral and cognitive benefits.

[Psychiatric and Social Aspects of Patients with Fragile X Syndrome]

OBJECTIVE

The goal of the study was to describe the burden of psychosocial risks, of mental illnesses and the ways of treatment of patients with fragile X syndrome (FRX).

METHOD

Data from a sample of 46 FRX-patients stemming from a prospective multicenter (N = 12) registry study (EXPLAIN) were analyzed with regard to psychosocial burden and treatment.

RESULTS

More than 50 % of all participants reported about relatives suffering from FRX, too. The majority of participants did not finish school and was suffering from one or another kind of mental problems. Younger participants (< 18 yrs.) tended to suffer from expansive disorders. Older participants were rather burdened by internalizing symptoms and disorders. Disorders were usually treated by psychotropic drugs added by logopedic therapies and occupational therapies (more than once a month). In our sample 90.6 % of younger and more than 64.3 % of older patients were still living with their parents.

CONCLUSIONS

Patients with FRX often suffer from additional mental disorders and should be diagnosed and treated early.

EXPLAIN Fragile-X: an explorative, longitudinal study on the characterization, treatment pathways, and patient-related outcomes of Fragile X Syndrome

BACKGROUND

Fragile X syndrome (FXS), caused by a mutation of the FMR1 gene on the X chromosome, is the most common inherited form of intellectual disability and autism spectrum disorders. Comprehensive data are lacking, however, on the characteristics and management patients with FXS in Germany.

METHODS/DESIGN

EXPLAIN is a prospective, observational, longitudinal registry with a non-probability sampling approach. It collects data on patient characteristics, therapeutic interventions, psychosocial parameters (including those of family members and caregivers), quality of life of caregiver and patient, caregiver burden, and health economic parameters, such as hospitalisation time. It is designed to include data from 300 patients in ambulatory care from about 50 centres that employ psychiatrists, paediatricians, neurologists, and other relevant specialists, in Germany. The study was initiated in March, 2013. Patients will be followed for at least two years.

DISCUSSION

The registry is expected to provide much-needed data on the characteristics and management of patients with FXS in Germany. It will also allow comparisons with other countries, and will enable gap analyses based on current guidelines for management of these patients.

TRIAL REGISTRATION

The ClinicalTrials.gov identifier is NCT01711606.

Dietary patterns and risk of breast cancer

Background:

Evidence is emerging that prudent/healthy dietary patterns might be associated with a reduced risk of breast cancer.

Methods:

Using data from the prospective Melbourne Collaborative Cohort Study, we applied principal factor analysis to 124 foods and beverages to identify dietary patterns and estimated their association with breast cancer risk overall and by tumour characteristics using Cox regression.

Results:

During an average of 14.1 years of follow-up of 20 967 women participants, 815 invasive breast cancers were diagnosed. Among the four dietary factors that we identified, only that characterised by high consumption of fruit and salad was associated with a reduced risk, with stronger associations observed for tumours not expressing oestrogen (ER) and progesterone receptors (PR). Compared with women in the lowest quintile of the factor score, the hazard ratio for women in the highest quintile was 0.92 (95% confidence interval (CI)=0.70–1.21; test for trend, P=0.5) for ER-positive or PR-positive tumours and 0.48 (95% CI=0.26–0.86; test for trend, P=0.002) for ER-negative and PR-negative tumours (test for homogeneity, P=0.01).

Conclusion:

Our study provides additional support for the hypothesis that a dietary pattern rich in fruit and salad might protect against invasive breast cancer and that the effect might be stronger for ER- and PR-negative tumours.

A sequence related to rice Pong transposable element displays transcriptional activation by in vitro culture and reveals somaclonal variations in maize

Miniature inverted-repeat transposable elements (MITEs) are nonautonomous elements that are abundant in plant genomes. The rice MITE mPing was shown to be mobilized by anther culture, and the associated transposon Pong was shown to transpose actively in an Oryza sativa 'indica' rice cell-culture line. We have identified 3 sequences in maize named ZmTPAPong-like 1, 2, and 3 that displayed homology with the transposase of Pong. Here, we show that these sequences are differentially expressed during the in vitro androgenetic process in maize. We also demonstrate that the ZmTPAPong-like 1 and 3 sequences reveal somaclonal variations among plants regenerated from the calli of a doubled haploid line. These data suggest that the ZmTPAPong-like sequences could form part of a Zea mays element related to the rice Pong element. The possible activation of this newly discovered element under stress conditions is discussed.

Development of a vaccine marker technology: Display of B cell epitopes on the surface of recombinant polyomavirus-like pentamers and capsoids induces peptide-specific antibodies in piglets after vaccination

Highly immunogenic capsomers (pentamers) and virus-like particles (VLPs) were generated through insertion of foreign B cell epitopes into the surface-exposed loops of the VP1 protein of murine polyomavirus and via heterologous expression of the recombinant fusion proteins in E. coli. Usually, complex proteins like the keyhole limpet hemocyanin (KLH) act as standard carrier devices for the display of such immunogenic peptides after chemical linkage. Here, a comparative analysis revealed that antibody responses raised against the carrier entities, KLH or VP1 pentamers, did not significantly differ up to 18 weeks, demonstrating the highly immunogenic nature of VP1-based particulate structures. The carrier-specific antibody response was reproducibly detected in the meat juice after processing. More importantly, chimeric VP1 pentamers and VLPs carrying peptides of 12 and 14 amino acids in length, inserted into the BC2 loop, induced a strong and long-lasting humoral immune response against VP1 and the inserted foreign epitope. Remarkably, the epitope-specific antibody response was only moderately decreased when VP1 pentamers were used instead of VLPs. In conclusion, we identified polyomavirus VP1-based structures displaying surface-exposed immunodominant B cell epitopes as being an efficient carrier system for the induction of potent peptide-specific antibodies. The application of this approach in vaccine marker technology in livestock holding and the meat production chain is discussed.

Murine polyomavirus-like particles induce maturation of bone marrow-derived dendritic cells and proliferation of T cells

We analysed the effects of murine polyomavirus-like particles (PLPs) on bone marrow-derived dendritic cells (BMDCs) and T cells in vitro. BMDCs activated with PLPs up-regulated CD40, CD80, CD86 and major histocompatibility complex (MHC) class II surface markers and produced proinflammatory cytokines. Chimeric PLPs [expressing the ovalbumin (OVA)-peptides OVA(257-264) or OVA(323-339)], but not wildtype PLPs, activated OVA-specific CD8 T cells and OVA-specific CD4 T cells, respectively, indicating both MHC class I and II presentation of the peptides by antigen-presenting cells. Our results suggest that PLPs may be used as vaccine adjuvants priming dendritic cells to induce potent T cell responses.

Beneficial therapeutic effects with different particulate structures of murine polyomavirus VP1-coat protein carrying self or non-self CD8 T cell epitopes against murine melanoma

Polyomavirus-like-particles (PLPs) are empty, non-replicative, non-infectious particles that represent a potent antigen-delivery system against malignant disease. Protective anti-tumour immunity can be induced under therapy conditions by subcutaneous (s.c.) treatment with particulate antigenic structures like chimerical polyomavirus-pentamers (PPs). These PPs displaying an immunodominant H-2Kb-restricted ovalbumin (OVA)257-264 epitope evoked nearly complete tumour remission in MO5 (B16-OVA) melanoma-bearing C57BL/6 mice by two s.c. applications in a weekly interval. The immunotherapeutic intervention started at day 4 after melanoma implant. Furthermore, 40% of melanoma-bearing mice vaccinated with heterologous PPs carrying a H-2Kb-restricted cytotoxic T lymphocyte (CTL) epitope derived from of tyrosinase-related protein 2 (TRP2) survived similar treatment conditions. However, a late immunotherapeutic onset at day 10 post melanoma inoculation revealed no significant differences between the therapeutic values (40-60% survival) of VP1-OVA252-270 and VP1-TRP2180-192 PPs, respectively. These experiments underlined the capacity of PPs to break T cell tolerance against a differentially expressed self-antigen. As a correlate for preventive and therapeutic immunity against MO5 melanoma the number of OVA257-264- or TRP2180-188-specific CD8 T cells were significantly increased within the splenocyte population of treated mice as measured by H-2Kb-OVA257-264-PE tetramer staining or appropriate ELISPOT assays, respectively. These results reveal that heterologous PLPs and even chimerical PPs represent highly efficient antigen carriers for inducing CTL responses underlining their potential as immunotherapeutics against cancer.

Identification of candidate genes for in vitro androgenesis induction in maize

Extensive studies have been conducted to understand the genetic control of in vitro androgenesis, but little is know about the genes and the mechanisms involved in the switch that allows an immature pollen grain to develop as an embryo. We have developed two maize isogenic lines with high androgenetic aptitude, named AH5-44 and AH5-49, through backcross and selection from a high-responsive DH229 line on the non-responding A188 line genetic background. The genomic structure of these two lines was precisely described with microsatellite markers. Five regions retained from the parent DH229 highly responsive to androgenesis were localised in both AH5-44 and AH5-49. Sequences expressed on microspores extracted from the four lines were amplified using a cDNA-AFLP protocol. For each line, eight culture conditions were compared: microspores extracted after tassel recovery, after 7 or 14 days in cold room and after 1-4 days of in vitro culture. This genetic and developmental screening allowed us to identify four sequences, including a new HSP70-like candidate gene. Possible implication of the identified sequences in androgenesis response is discussed.

Resting metabolic rate, body composition and aerobic fitness comparisons between active and sedentary 54-71 year old males

OBJECTIVE

To test the hypothesis that 55-70 y old male longterm exercisers (LE) have higher resting metabolic rates (RMR) than longterm nonexercisers (LNE).

DESIGN

A power analysis demonstrated that this cross-sectional study required 12 subjects per group to detect a 10% RMR difference (kJ x kg FFM(-1) x d(-1)) between the LE and LNE (power = 0.8;alpha = 0.05).

SUBJECTS

Twelve LE (X +/- s.d.; 63.5+/-3.4 y; 1.75+/-0.06 m; 69.01+/-8.24 kg; 20.4+/-4.9 %BF) and 12 LNE (63.6+/-5.6 y; 1.72+/-0.07 m; 79.44 12.4 kg; 29.6 4.4 %BF) were recruited from advertisements placed in a newspaper and on university and community noticeboards.

INTERVENTIONS

Measurements were conducted for: RMR using the Douglas bag technique; body composition via a four compartment model which is based on determination of body density, total body water and bone mineral mass; and aerobic fitness using a submaximal work test on a cycle ergometer.

RESULTS

The LE (93.00+/-7.16 kJ x kg(-1) x d(-1)) registered a significantly greater (P = 0.04) RMR than the LNE (84.70+/-11.23 kJ x kg(-1) x d(-1)) when energy expenditure was expressed relative to body mass, but this difference disappeared (P = 0.55) when the data were corrected for the non-zero intercept of the graph of RMR (MJ/d) against body mass. ANCOVA with FFM as the covariate also indicated that the RMR (MJ/d) difference between the groups was not statistically significant (P = 0.28). The adjusted means for the LE and LNE were 6.39 and 6.62 MJ/d, respectively.

CONCLUSIONS

There are no RMR (MJ/d) differences between LE and LNE 54-71 y old males when statistical control is exerted for the effect of FFM and the higher value of the former group for RMR normalised to body mass disappears when this ratio is corrected for statistical bias.

Energy metabolism in sedentary and active 49- to 70-yr-old women

This study examined differences between long-term exercising (LE) and long-term nonexercising (LNE) women [n = 24; age 56.4 +/- 6.2 (SD) yr] for resting metabolic rate (RMR) and energy expenditure in the free-living state by using doubly labeled water (DLW). There was a statistically significant difference (P = 0.0002) between the 12 LE (94.85 +/- 8.44 kJ . kg-1 . day-1) and 12 LNE (81.16 +/- 6.62 kJ . kg-1 . day-1) for RMR, but this difference was only marginally significant (P = 0.06) when the data (MJ/day) were subjected to an analysis of covariance with fat-free mass as the covariate. The DLW data indicated that the eight most active LE (12.99 +/- 3.58 MJ/day) expended significantly (P = 0.01) more energy than did the eight least active LNE (9.30 +/- 1.15 MJ/day). Energy expenditures ranged from 7.64 to 18.15 MJ/day, but there was no difference (P = 0.96) between the LE and LNE in energy expenditure during activity that was not designed to either improve or maintain fitness. These cross-sectional data on 49- to 70-yr-old women therefore suggest that 1) aerobic-type training results in a greater RMR per unit of body mass and also when statistical control is exerted for the effect of the metabolically active fat-free mass, 2) there is a large range in the energy intake necessary to maintain energy balance, and 3) aerobic training does not result in a compensatory reduction in energy expenditure during the remainder of the day.

Relationship between maximum aerobic power and resting metabolic rate in young adult women

The literature is inconclusive as to the chronic effect of aerobic exercise on resting metabolic rate (RMR), and furthermore there is a scarcity of data on young women. Thirty-four young women exhibiting a wide range of aerobic fitness [maximum aerobic power (VO2max) = 32.3-64.8 ml.kg-1.min-1] were accordingly measured for RMR by the Douglas bag method, treadmill VO2max, and fat-free mass (FFM) by using Siri's three-compartment model. The interclass correlation (n = 34) between RMR (kJ/h) and VO2max (ml.kg-1.min-1) was significant (r = 0.39, P < 0.05). However, this relationship lost statistical significance when RMR was indexed to FFM and when partial correlation analysis was used to control for FFM differences. Furthermore, multiple linear-regression analysis indicated that only FFM emerged as a significant predictor of RMR (kJ/h). When high- (n = 12) and low-fitness (n = 12) groups were extracted from the cohort on the basis of VO2max scores, independent t-tests revealed significant between-group differences (P < 0.05) for RMR (kJ.kg-1.h-1) and VO2max (ml.kg-1.min-1) but not for RMR (kJ/h), RMR (kJ.kg FFM-1.h-1), and FFM. Analysis of covariance of RMR (kJ/h) with FFM as the covariate also showed no significant difference (P = 0.56) between high- and low-fitness groups. Thus the results suggest that 1) FFM accounts for most of the differences in RMR between subjects of varying VO2max values and 2) the RMR per unit of FFM in young healthy women is unrelated to VO2max.

Differences in substrate metabolism between self-perceived 'large-eating' and 'small-eating' women

OBJECTIVE

To compare different aspects of intermediary metabolism in self perceived 'small-eating' females and self-perceived near normal weight 'large-eating' females and relate the data to those reported for Pima Indians who have the world's highest prevalence of non-insulin dependent diabetes mellitus and obesity.

DESIGN

Make repeat measurements of rates of oxygen consumption, carbon dioxide production and blood metabolites in 'large-' and 'small-eating' females at rest, during different activities and after ingestion of a standardised liquid meal.

SUBJECTS

Nine self perceived, 'large-eating' females and nine self perceived 'small-eating' females.

MEASUREMENTS

Resting metabolic rates (RMR), respiratory quotient (RQ) values and plasma insulin, glucagon insulin-like growth factor (IGF-1), dehydroepiandrosterone sulphate (DHEA-SO4) and glucose.

RESULTS

RMR (adjusted for FFM) averaged 3891 +/- 93 J/min in the 'small-eaters' and 3375 +/- 107 J/min in the 'large-eaters' for ten consecutive measurements conducted at 30 min intervals during the control period for the measurement of the thermic effect of food. Over this period the average RQ for the 'small-eating' women (0.81) was significantly greater than that of the 'large-eating' women (0.78). The two groups responded similarly to an oral glucose tolerance test but the concentration of DHEA-SO4 in plasma was 35% higher in the 'small-eaters'.

CONCLUSION

The 'small-eating' women may have a greater risk of weight gain but they counteract this tendency by maintaining high activity levels.

Energy metabolism in free-living, 'large-eating' and 'small-eating' women: studies using 2H2(18)O

The doubly-labelled water (2H2(18)O) technique was used to assess the long-term rates of energy expenditure and, after accounting for any changes in body composition, the derived rates of energy intake in weight-stable 'large-eating' (n 6) and 'small-eating' (n 6) women. The self-reported energy intakes (approximately 11.2 v. 5.6 MJ/d) and energy expenditures (approximately 8.5 v. 12.4 MJ/d) for the 'large-eating' and 'small-eating' groups respectively, should not be sustainable without significant body-weight changes. 2H2(18)O-assessed rates of energy expenditure for the 'large-eaters' (approximately 8.5 MJ/d) and 'small-eaters' (approximately 11.3 MJ/d) were in close agreement with the results obtained using 5 d, self-reported activity diaries but the derived rates of energy intake for the 'large-' (approximately 8.5 MJ/d) and 'small-eaters' (approximately 10.8 MJ/d) were markedly different from those obtained using self-reported, weighed food diaries. When two 'small-eaters' were supplied with their self-reported energy intakes (approximately 5 MJ/d) for up to 28 d both subjects lost about 0.75 kg body-weight/week. These results provide no support for the existence of 'metabolically efficient' women in the community.

No major differences in energy metabolism between matched and unmatched groups of 'large-eating' and 'small-eating' men

Rates of energy expenditure (J/kg fat-free mass (FFM) per min) in normal weight, 'small-eating' men were compared with those obtained for normal weight (n 8) and underweight (n 5) 'large-eating' men. For the matched groups of 'large-' and 'small-eaters' there were no differences in resting metabolic rate (RMR) measurements but during controlled daily activities there was a small but significant increase (P < 0.05) in energy expenditure in the 'large-eaters'. These results contrast with those obtained for the unmatched groups where energy requirements were about 10% (P < 0.01) higher in the underweight 'large-eaters' at rest but were not different during the more energetic (walking) activities. However, after adjustment for differences in FFM between these two groups, the resting energy expenditures of the 'large-eaters' (82.54 (SE 1.51) J/kg FFM per min) were similar to those of the 'small-eaters' (81.87 (SE 1.51) J/kg FFM per min). Oral temperatures were significantly higher in the matched (0.35-0.65 degrees) and unmatched (0.7-0.9 degrees) 'large-eaters' both at rest and during the different activities, but the thermic effect of food (50 kJ/kg FFM) was one fifth lower (not significant) in both groups of 'large-eaters'. These results provide little evidence for any major metabolic differences between groups of 'large-eating' and 'small-eating' men.

No differences in rates of energy expenditure between post-obese women and their matched, lean controls

Rates of energy expenditure at rest, during different daily activities and following a standardized liquid meal were compared in eight post-obese women, with a mean weight loss of 21.5 kg (range 14.1 to 33.3 kg) and eight controls who had never been overweight. Age, height, body mass index, fat-free mass and average daily energy intake were similar for both experimental groups. Resting metabolic rate averaged 23.04 cal/min/kg FFM (s.e.m. 1.14) in the post-obese and 22.70 cal/min/kg FFM (s.e.m. 0.64) in the controls on their first visit to the laboratory. Metabolic rates in the two groups rose in parallel as energy expenditure was increased by sitting, standing and walking at three different speeds (2.4, 3.9 and 5.4 km/h). At the highest walking speed energy expenditure averaged 95.30 cal/min/kg FFM (s.e.m. 4.18) in the post-obese and 93.42 cal/min/kg FFM (s.e.m. 2.97) in the control women. Comparisons of postprandial thermogenesis revealed no significant differences between the two groups. The results of the present study do not support the thesis that rates of energy expenditure, whether at rest, during different activities, or after eating, are reduced in post-obese women.

Differences in energy metabolism between normal weight 'large-eating' and 'small-eating' women

Nine 'large-eating' (approximately 12 MJ/d) and nine 'small-eating' (approximately 5.3 MJ/d) women were selected from the population on the basis of diet and activity diaries. At rest and in the post-absorptive state the rate of oxygen consumption (VO2)/kg fat-free mass (FFM) and rate of carbon dioxide production (VCO2)/kg FFM were 9-17% higher (P < 0.05) in the 'large-eaters' than in the 'small-eaters'. As energy expenditure was increased by walking at 2.4, 3.9 and 5.4 km/h the differences between the two experimental groups for both VO2/kg FFM and VCO2/kg FFM were decreased to negligible values, but energy expended on a body-weight basis (MJ/kg per min) remained significantly higher (5-10%) in 'large-eaters'. Oral temperature was also consistently higher (up to 0.5 degrees) in this group both at rest and during sitting, standing and walking activities. Although the average thermic effect of a standardized liquid meal tended to be higher (27%; not significant) in the 'small-eaters', the other results demonstrate that the 'large-eating' females had a markedly higher rate of energy expenditure at rest and during light physical activities.

Some effects of different extracellular proteins on oxygen consumption and heat production in isolated rat hepatocytes

When hepatocytes prepared from 24-h-fasted rats were washed, suspended and incubated in Krebs-Henseleit bicarbonate-buffered saline, the endogenous rates of O2 consumption and heat production were 2.13 +/- 0.13 mumol/min per g wet wt. and 1.00 +/- 0.05 J/min per g wet wt. respectively. The inclusion of 2.5% (w/v) defatted and dialysed bovine serum albumin in either the cell suspension (washing) buffer or the cell incubation buffer produced a 20-25% increase in O2 consumption and heat production: these rates were increased by an additional 20-25% when the albumin (2.5%) was present in both the cell suspension and the cell incubation buffers. There was an inverse relationship between the increases in O2 consumption and heat production and the leakage of lactate dehydrogenase from the isolated hepatocytes: the inclusion of purified bovine serum albumin decreased lactate dehydrogenase leakage from 40% to 15% of total enzyme content. The calorimetric-respirometric ratios for hepatocytes incubated both in the absence (-461 +/- 19 kJ/mol O2) and presence (-477 +/- 8 kJ/mol O2) of the purified protein are very similar to the theoretical, thermochemically derived oxycaloric equivalents.

Muscle metabolism during 30, 60 and 90 s of maximal cycling on an air-braked ergometer

This study examined the anaerobic and aerobic contributions to muscle metabolism during high intensity short duration exercise. Six males [mean (SD): age 25.0 (6.0) years, height 179.0 (8.2) cm, mass 70.01 (7.42) kg, VO2max 4.63 (0.53) l.min-1, body fat 12.7 (2.3)%] performed three counterbalanced treatments of 30, 60 and 90 s of maximal cycling on an air-braked ergometer. All treatments were also performed on days when biopsies were not taken from the vastus lateralis muscle and cannulae not inserted into a forearm vein to ascertain whether these procedures adversely affected performance. The mean results can be summarised as follows: (Table: see text). The muscle lactate and O2 deficit data suggested that 60 and 90 s were more appropriate durations than 30 s for assessing the anaerobic capacity on an air-braked cycle ergometer. The mean power outputs also indicated that the invasive procedures did not adversely affect performance [corrected].

Age-related augmentation of phosphorylase b kinase in hepatic tissue from the glycogen-storage-disease (gsd/gsd) rat

The effects of food deprivation on body weight, liver weight, hepatic glycogen content, glycogenolytic enzymes and blood metabolites were compared in young and old phosphorylase b kinase-deficient (gsd/gsd) rats. Although the concentration of glycogen in liver from 9-week-old female gsd/gsd rats (730 mumol of glucose equivalents/g wet wt.) was increased by 7-8% during starvation, total hepatic glycogen was decreased by 12% after 24 h without food. In 12-month-old male gsd/gsd rats the concentration of liver glycogen (585 mumol of glucose equiv./g wet wt.) was decreased by 16% and total hepatic glycogen by nearly 40% after food deprivation for 24 h. Phosphorylase b kinase and phosphorylase a were present at approx. 10% of the control activities in 9-week-old gsd/gsd rats, but both enzyme activities were increased more than 3-fold in 12-month-old affected rodents. It is concluded that the age-related ability to mobilize hepatic glycogen appears to result from the augmentation of phosphorylase b kinase during maturation of the gsd/gsd rat.

Microcalorimetric measurements of heat production in brown adipocytes from control and cafeteria-fed rats

The effects of the sequential addition of glucose, noradrenaline, propranolol and oleic acid on the rates of O2 consumption and heat production by isolated interscapular brown adipocytes from control and cafeteria-fed rats were compared. Although the chemical agents produced very similar changes in oxidative metabolism, the actual rates of O2 uptake and heat output in adipocytes from the cafeteria-fed rats, when expressed per g dry wt. of cells, were approx. 65% less than those obtained with cells from the control rats. However, when the same results were expressed per 10(8) multiloccular brown adipocytes, rather than gravimetrically, rates of O2 consumption and heat production were equivalent. Further interpretation of these data is complicated, because the average volume of multiloccular brown adipocytes from cafeteria-fed rats was 2.5 times that for multiloccular cells from control animals.

Effects in vivo of food deprivation and 3-mercaptopicolinate in the glycogen-storage-disease (gsd/gsd) rat

Intraperitoneal injection of 3-mercaptopicolinate into 24 h-food-deprived 27-week-old female control (GSD/GSD) rats lowered the concentration of circulating glucose by 66%, but glycerol and lactate concentrations were increased up to 3- and 4-fold respectively. In phosphorylase b kinase-deficient (gsd/gsd) rats the corresponding changes for blood glucose, lactate and glycerol were half those observed in the controls. Although the concentration of liver glycogen (approx. 12%, w/w) in the gsd/gsd rats was not altered during food deprivation, total hepatic glycogen was decreased by 17%. It is suggested that the gradual breakdown of the extensive hepatic glycogen stores during starvation assists in the maintenance of normoglycaemia in the gsd/gsd rat.

No major thermogenic role for (Na+ + K+)-dependent adenosine triphosphatase apparent in hepatocytes from hyperthyroid rats

(Na+ + K+)-dependent ATPase activity, heat production and oxygen consumption were increased by 59%, 62% and 75% respectively in hepatocytes from tri-iodothyronine-treated rats. Ouabain at concentrations of 1 and 10 mM decreased oxygen uptake by 2--8% in hepatocytes from euthyroid rats and by 5--15% in hepatocytes from hyperthyroid animals. Heat output was decreased by 4--9% with the glycoside in isolated liver parenchymal cells from the control animals and by 11% in the cells from the tri-iodothyronine-treated animals. These results do not support the hypothesis that hepatic (Na+ + K+)-ATPase plays a major role in increased heat production in hepatocytes from hyperthyroid rats.

Glycogen metabolism in the liver of the neonatal gsd/gsd and control (GSD/GSD) rat

1. The metabolism of hepatic glycogen, labelled with [6-3H]glucose at day 19.5 of gestation and with 14C from [U-14C]galactose at delivery, was followed for 10 h in food-deprived gsd/gsd and control (GSD/GSD) neonatal rats. 2. In the affected pups glycogen was maintained at 12% (w/w) and there was no loss of incorporated radioactivity. 3. The 3H and 14C in glycogen from the controls were both decreased by 80%, but 14C was removed at 0--5 h and [6-3H]glucose at 5--10 h. 4. Blood glucose concentrations in the unaffected neonatal rats fell from 5.3 mM at 20 min to 1.7 mM after 10 h. In the gsd/gsd pups blood glucose concentration was decreased from 2 mM at birth to 0.3 mM at 2.5 h: it was maintained at 0.8 mM between 5 and 10 h. 5. In neonatal rats that had been dead for 10 h, hepatic glycogen was decreased by 34% in the controls and by 22% in the gsd/gsd pups. These results demonstrate that liver from the affected rats contains glycogenolytic activity, but that it is not expressed in living tissue.

A study of blood coagulation parameters

The object of this study was to determine the presence or absence of abnormalities in a variety of blood coagulation parameters in women on contraceptive medication. A prospective double-blind study involving a control group with a total study enrollment of 211 women during a 29 month period was established. Although research has not proved that changes in coagulation parameters will cause abnormal clotting in normal patients, a pattern appears to be developing involving antithrombin III determinations. Corresponding patterns do not appear to be developing in the other blood coagulation parameters.