Structurally stable but functionally disrupted marine microbial communities under a future climate change scenario: Potential importance for nitrous oxide emissions

The blue mussel Mytilus edulis is a widespread and abundant bivalve species along the North Sea with high economic and ecological importance as an engineer species. The shell of mussels is intensively colonized by microbial organisms that can produce significant quantities of nitrous oxide (N2O), a potent greenhouse gas. To characterize the impacts of climate change on the composition, structure and functioning of microbial biofilms on the shell surface of M. edulis, we experimentally exposed them to orthogonal combinations of increased seawater temperature (20 vs. 23 °C) and decreased pH (8.0 vs. 7.7) for six weeks. We used amplicon sequencing of the 16S rRNA gene to characterize the alpha and beta diversity of microbial communities on the mussel shell. The functioning of microbial biofilms was assessed by measuring aerobic respiration and nitrogen emission rates. We did not report any significant impacts of climate change treatments on the diversity of mussel microbiomes nor on the structure of these communities. Lowered pH and increased temperature had antagonistic effects on the functioning of microbial communities with decreased aerobic respiration and N2O emission rates of microbial biofilms in acidified seawater compared to increased rates in warmer conditions. An overriding impact of acidification over warming was finally observed on N2O emissions when the two factors were combined. Although acidification and warming in combination significantly reduced N2O biofilm emissions, the promotion of aquaculture activities in coastal waters where shellfish do not normally occur at high biomass and density could nonetheless result in unwanted emissions of this greenhouse gas in a near future.

Changes in daily leptin, ghrelin and adiponectin profiles following a diet with carbohydrates eaten at dinner in obese subjects

BACKGROUND AND AIMS

Our recently published randomised clinical trial evaluated the effect of a low-calorie diet with carbohydrates eaten at dinner. This dietary pattern led to lower hunger scores, and better anthropometric, biochemical and inflammatory outcomes compared to a standard low-calorie diet. In the same study, changes in diurnal secretion patterns of leptin, ghrelin and adiponectin were investigated.

METHODS AND RESULTS

Seventy-eight police officers (body mass index (BMI) > 30) were randomly allocated to experimental (carbohydrates at dinner) or control weight loss diets for 6 months. Sixty-three subjects finished the programme. On days 0, 7, 90 and 180 blood samples and hunger scores were collected every 4 h from 8:00 to 20:00. Hormonal profiles were available for 39. The dietary manipulation led to changes in daylight hormonal profiles in the experimental group. Leptin's secretion curve became convex, with a nadir later in the day (significant difference compared to baseline at morning and evening, p = 0.023, p = 0.021, respectively). Ghrelin's secretion curve became concave, peaking only in the evening hours. Adiponectin's curve was elevated only after the experimental diet (significant difference compared to baseline at afternoon, p = 0.044).

CONCLUSIONS

We propose that a low-calorie diet with carbohydrates eaten at dinner can modulate daytime hormonal profiles. Taken together with our earlier results, we believe this diet regime may prevent mid-day hunger, better support weight loss and improve metabolic outcomes compared to conventional weight loss diets. The trial is registered at controlled-trials.com, ISRCTN37829376, December 2009.

Effects of GnRH administered to cows at the onset of estrus on timing of ovulation, endocrine responses, and conception

Two experiments examined effects of GnRH administered within 3 h after onset of estrus (OE) on ovulation and conception in dairy cows. In experiment 1, 46 cows received either saline, 250 microg of GnRH, or 10 microg of the GnRH analogue, Buserelin. Cows were observed for estrus, blood samples were collected, and ovulations were monitored by ultrasound. In controls, 76% of cows had intervals from estrus to ovulation of < or = 30 h and 24% had intervals > 30 h. Treatment with either GnRH or GnRH analogue (data combined) increased magnitude of LH surges and decreased intervals from estrus to LH surge or to ovulation. Treated cows all ovulated < or = 30 h after OE. Among control cows, plasma estradiol concentrations before estrus correlated positively with amplitudes of LH surges. Higher plasma progesterone was observed in the subsequent estrous cycle in GnRH-treated cows compared to control cows with delayed ovulations. Experiment 2 included 152 primiparous and 211 multiparous cows in summer and winter. Injection of GnRH analogue at OE increased conception rates (CR) from 41.3 to 55.5% across seasons. In summer, GnRH treatment increased CR from 35.1 to 51.6%. Across seasons, GnRH increased CR from 36.0 to 61.5% in cows with lower body condition at insemination and GnRH increased CR (63.2 vs. 42.2%) in primiparous cows compared to controls. Use of GnRH eliminated differences in CR for cows inseminated early or late relative to OE and increased CR in cows having postpartum reproductive disorders. In conclusion, GnRH at onset of estrus increased LH surges, prevented delayed ovulation, and may increase subsequent progesterone concentrations. Treatments with GnRH increased conception in primiparous cows, during summer, and in cows with lower body condition.

Orbitofrontal cortex dysfunction in obsessive-compulsive disorder? I. Alternation learning in obsessive-compulsive disorder: male-female comparisons

BACKGROUND

We have previously reported a significant negative correlation between severity of symptoms and performance of an alternation learning task in female obsessive-compulsive disorder (OCD) patients. The present study was aimed at exploring this relationship between alternation learning and OCD symptom severity in male OCD patients.

METHODS AND RESULTS

Eighteen female obsessive-compulsive disorder patients and 14 male non-depressed, drug free, OCD patients participated in the study. Measures of dorsolateral prefrontal function (Wisconsin Card Sorting Test) and orbitofrontal cortex function (object alternation learning) showed no significant differences between the sexes. The relationship between orbitofrontal cortex function and severity of OC symptoms was significantly different between the sexes (z=2.44. P=0.007). While this correlation was negative in the females it was positive in the males.

CONCLUSIONS

These results may indicate sexual dimorphism in OCD.

Orbitofrontal cortex dysfunction in obsessive-compulsive disorder? II. Olfactory quality discrimination in obsessive-compulsive disorder

BACKGROUND

Olfactory quality discrimination is a putative marker of orbitofrontal cortex function in mammals. As this portion of the cerebral cortex was repeatedly implicated in the pathophysiology of obsessive-compulsive disorder (OCD) this study was designed in an attempt to quantify this behavioural function in OCD patients.

METHODS AND RESULTS

Olfactory quality discrimination was compared in OCD patients and healthy controls. Thirty two subjects participated in the study: 16 (13 women and 3 men) medication free OCD outpatients and 16 sex and age matched healthy controls. Olfactory tests consisted of determination of detection thresholds to isoamyl acetate, and a three way forced choice quality discrimination task, using isoamyl acetate, citral and eugenol as stimuli. No significant differences in sensitivity and performance of the quality discrimination task between the two groups were found. Within the OCD group the more severely affected patients (Y-BOCS>29) performed significantly better than the less severely affected (Y-BOCS<30) patients on the more difficult part of the quality discrimination task. Within this subgroup of patients the correlation between performance on the olfactory task and a previously reported alternation task tended to be negative as compared to a significantly positive correlation in the control group.

CONCLUSIONS

It seems that olfactory quality discrimination may prove to be a useful noninvasive marker of prefrontal cortex function in OCD. Furthermore, the organization of functional modules within the orbitofrontal cortex, rather than a simple dysfunction, may prove to characterize OCD.

The suicide brain: a review of postmortem receptor/transporter binding studies

The present review summarizes the last 15 years of research involving postmortem receptor/transporter binding studies on brains of suicide victims. It is our working hypothesis, on the basis of psychological, behavioral and epidemiological studies, that suicidal behavior is an independent unique behavioral entity with specific neurochemical characteristics. This review tries to test this hypothesis at the level of neurotransmitter receptors by using a different approach to data analysis. We suggest that this statistical approach, involving multivariate analyses, can contribute to the formulation of new hypotheses at the level of molecular biology and genetics. Such studies if undertaken in the future, would help define suicidal behavior as a psycho-neuro-pathological entity.

The effect of enhanced milk yield of dairy cows by frequent milking or suckling on intake and digestibility of the diet

Groups of 9 or 10 cows were assigned to one of three treatments 1) machine-milking three times daily, 2) machine-milking six times daily, and 3) suckling three times daily in addition to machine-milking three times daily. Treatments were conducted during the first 6 wk postpartum. During wk 5, digestibility of the diet was estimated by the indigestible neutral detergent fiber method. During wk 6, milk yield and dry matter intake (DMI) were recorded daily, and plasma concentrations of glucose, nonesterified fatty acids, urea, protein, growth hormone, insulin, insulin-like growth factor I, oxytocin, and prolactin were determined. Milk yields were 38.5, 46.8, and 52.7 kg/d, and DMI were 18.1, 21.2, and 17.2, for cows on treatments 1, 2, and 3, respectively. Plasma glucose concentrations decreased, and plasma nonesterified fatty acid concentrations increased, for cows on treatments 2 and 3 compared with cows on treatment 1. Digestibility of dry matter was 57.5, 60.5, and 60.6%; of organic matter was 62.6, 64.6, and 66.8%; and of crude protein was 59.3, 62.7, and 64.6% for cows on treatments 1, 2, and 3, respectively. Concentrations of all assayed hormones, except insulin, increased moderately for cows on treatment 2 compared with cows on treatment 1 and increased dramatically for cows on treatment 3. Insulin concentrations followed the opposite trend. The DMI were positively related to milk yields and negatively related to oxytocin concentrations. Digestibility was negatively related to plasma glucose concentrations in a nonlinear pattern. The possible involvement of hormones in improvement of digestibility is discussed.

Investigation of splenic functions in canine monocytic ehrlichiosis

In order to determine the role of the spleen in the pathogenesis of canine monocytic ehrlichiosis (CME), the effect of splenectomy on the course of the acute phase of experimental was investigated. Intact and splenectomized dogs, sero-negative for Ehrlichia canis antibodies, were infected with the Israeli strain of E. canis. Serology, clinical signs and haematological parameters were recorded prior to infection, and over a period of 60 days post infection, and were compared between the intact and the splenectomized dogs. All dogs seroconverted for IFA E. canis antibodies by days 10 to 17 post infection. There did not appear to be any difference in the day of appearance or in the titer of anti-E. canis IgG antibodies, between the splenectomized and intact groups throughout the course of the study. During the acute stage, food consumption (percentage change) was significantly lower in the intact group compared to the splenectomized group (-66.3% and -25.3%, respectively, p < 0.0001). During this period, significant higher body temperatures were measured in the intact group (average of 39.76 degrees C vs. 38.96 degrees C, p < 0.0001). The haematocrit, red blood cell counts, haemoglobin concentrations and platelet counts were significantly lower (p < 0.05) in the intact group when compared to the splenectomized group during the whole course of the study. The clinical and the haematological findings in our study suggest that the disease process was milder in the splenectomized dogs compared to the intact dogs. The results of this study suggest that the spleen plays an important role in the pathogenesis of CME. Splenic inflammatory mediators and/or other splenic substances, are proposed to play a key role in the pathogenesis of the disease. Our results further substantiate the involvement of immune mechanisms in the pathogenesis of CME.

Increased weight gain and effects on production parameters of Holstein heifer calves that were allowed to suckle from birth to six weeks of age

Forty Holstein heifer calves were assigned to two treatments. Control calves (n = 20) were fed milk replacer in open buckets, and calves that were allowed to suckle (n = 20) were paired and suckled the same dam three times daily. Treatments were conducted during the first 6 wk following birth; thereafter, all calves received the same management, and weaning was at 60 d of age. During treatment, calves that were allowed to suckle had significantly higher average daily gains than did control calves. However, at 12 wk of age, calves that were allowed to suckle had significantly lower body weights (BW) than did control calves. Age at conception was significantly lower, and BW at conception and conception rate tended to be higher, for calves that were allowed to suckle. Calving age was significantly earlier for heifers that had been allowed to suckle as calves, and BW at calving also tended to be higher. Height at the withers after calving was also significantly higher for those heifers. Milk production during first lactation tended to be higher for the heifers that had been allowed to suckle as calves. Our results indicated that heifer calves that suckled milk during the first 42 d of age had higher average daily gains, higher height at the withers, an earlier age at calving, and a tendency for greater milk production than did calves fed milk replacer.

Effect of the degradation of organic matter and crude protein on ruminal fermentation in dairy cows

The potential of the dacron bag technique to assess fluctuations in ruminal metabolites was studied using 40 Israeli-Friesian dairy cows assigned to an experiment with a 2 x 2 factorial design. Diets contained a low (62%) or high (65%) percentage of ruminally degradable CP and a low (55%) or high (59%) percentage of ruminally degradable OM. Metabolites were monitored before feeding and at 3 and 6 h postfeeding. Before feeding, total VFA and propionate were higher, and acetate and pH were lower, in diets containing a high percentage of ruminally degradable OM than in diets containing a low percentage of degradable OM. By 3 H postfeeding, acetate, butyrate and pH were lower, and propionate was higher, in the diets containing a high percentage or ruminally degradable OM than in the diets containing a low percentage of ruminally degradable OM. By 6 h postfeeding, propionate was higher, and acetate was lower, in diets containing a high percentage of ruminally degradable OM than in diets containing a low percentage of ruminally degradable OM. In the diets with a high percentage of ruminally degradable OM, before feeding and by 3 h postfeeding, ammonia concentrations were higher and lower, respectively, relative to the diets containing a low percentage of degradable OM. Milk yield and composition and DMI were similar among treatments. The correlation was good between the degradability data obtained by the dacron bag technique and the meal-induced variations in ruminal metabolites. The lack of a positive yield response to controlled fluctuations in ruminal metabolites may be related to surplus CP intake.

Effect of breakfast timing on the cognitive functions of elementary school students

OBJECTIVE

To study the effect of breakfast timing on selected cognitive functions of elementary school students.

DESIGN

A 2-week randomized control intervention trial.

SETTING

Five elementary schools.

SUBJECTS

The subjects comprised 569 children, 51% of them boys, aged 11 to 13 years; the children were in grades 5 through 6 (17 classes). The subjects lived in different areas and had different socioeconomic backgrounds.

INTERVENTION

Each subject was tested twice, by 2 versions of the Rey Auditory-Verbal Learning Test, 2 alternative forms of the logical memory subtest of the revised Wechsler Memory Scale, and 2 versions of the Benton Visual Retention Test. On the first test, before any nutritional intervention, the subjects were asked to complete a questionnaire about their food intake on the day of testing. Two thirds of the subjects received 200 ml of 3%-fat milk and 30 g of sugared cornflakes for the next 14 days, and all the subjects were reexamined on the 15th day.

MAIN OUTCOME MEASURE

Scoring on the different tests was compared with baseline scores.

RESULTS

After 15 days, children who ate breakfast at school scored notably higher on most of the test modules than did children who ate breakfast at home and children who did not at breakfast.

CONCLUSIONS

Our results indicate that routinely eating breakfast 2 hours prior to being tested does not improve cognitive functions in 11- to 13-year-old elementary school students, but food supplementation 30 minutes prior to taking a test notably improves scoring. We suggest further studies on the relationship between meal content, feeding time, and scholastic performance.

Alternation learning in obsessive-compulsive disorder

The Wisconsin Card Sorting Test (WCST) and an alternation learning task were administered to 15 women with obsessive-compulsive disorder (OCD) and 15 age-, sex-, education-, and intelligence-matched healthy controls. OCD patients were significantly slower on the WCST as compared to the controls. Their performance on the alternation learning task was impaired relative to the control group, though this difference was diminished when we used education as a covariate. We found a significant positive correlation between performance on the alternation task and severity of symptoms in the OCD group. Performance of similar alternation tasks is impaired by damage to the orbitofrontal cortex in nonhuman primates. Therefore the data presented support the hypothesis of orbitofrontal cortex dysfunction in OCD.

Weight perception of adolescent dancing school students

OBJECTIVE

To study the hypothesis that underweight may be more prevalent among dancing school students than among nondancing school girls, and that their teachers and peers may play a role in developing this tendency.

DESIGN

A case-control study on a convenience sample.

SETTING

Two local dancing schools and one neighboring regular school.

PARTICIPANTS

Forty ballet students, aged 13 to 17 years, from four classes and 29 age-matched girls in four regular classes.

INTERVENTION

None.

MEASUREMENTS/MAIN RESULTS

Each pupil was asked to classify herself and her peers as underweight, normal, or overweight; teachers were asked to classify their pupils by the same categories. Results were compared with an objective score, weight as a percentage of ideal weight for height, in which less than 85% indicates underweight; 85% to 115%, normal; and more than 115%, overweight. A higher prevalence of underweight as well as a significant tendency to overestimate self-evaluation was found among dancing students. Dancing teachers' evaluation tended to be inaccurate, especially regarding their underweight students.

CONCLUSIONS

The atmosphere in dancing classes may encourage striving for thinness beyond normal limits. Ballet teachers may play a significant role in this process. We suggest that physicians and nutritionists be involved in ballet schools.

Relationship between frequent milking or suckling in early lactation and milk production of high producing dairy cows

Groups of 9 or 10 cows were assigned to one of three treatments 1) machine-milking three times daily, 2) machine-milking six times daily, and 3) suckling three times daily in addition to machine- milking three times daily. Treatments were conducted during the first 6 wk postpartum; thereafter, all cows were milked three times daily. During treatment, milk production was highest for suckled cows and lowest for cows milked three times daily. The DMI were similar for suckled cows and cows milked three times daily but higher for those milked six times daily. Body weight loss was greatest for suckled cows and least for cows milked three times daily. During wk 7 to 18 postpartum, cows milked six times daily exhibited a carry-over effect on milk production that was greater than that of other groups, During treatment, plasma growth hormone and IGF-I concentrations were elevated for suckled cows and, to a lesser extent, for cows milked six times daily. Prolactin and oxytocin similarly increased, but insulin decreased in suckled cows and, to a lesser extent, in cows milked six times daily. Posttreatment differences persisted for insulin and IGF-I, but not for the other hormones. Increased frequency of udder emptying increased milk production, and suckling was superior to machine-milking. High milk production was associated with elevated growth hormone, IGF-I, prolactin, and oxytocin, although cause and effect could not be established. The failure of suckled cows to increase feed intake to match output requires further investigation.

Enrichment of an Israeli ethnic food with fibres and their effects on the glycaemic and insulinaemic responses in subjects with non-insulin-dependent diabetes mellitus

The effects of various sources of dietary fibre on the high glycaemic index of an Israeli ethnic food, melawach, were investigated in subjects with non-insulin-dependent diabetes mellitus (NIDDM). Locust-bean (Ceratonia siliqua) gum significantly decreased the glucose response to, and glycaemic index of, melawach in these diabetic subjects (P < 0.05). It also tended to decrease their insulinaemic response and insulinaemic index, but differences were not significant. Dietary fibre from lupin (Lupinus albus) and insoluble maize-cob fibre did not affect glucose and insulin levels in NIDDM volunteers. Subjects with a BMI < 30 kg/m2 exhibited similar glucose, but not insulin, responses to fibre. Locust-bean gum had no significant effect on glycaemic response in NIDDM subjects with a BMI > 30 kg/m2, whereas insulinaemic response decreased. The results indicate that foods containing the same nutrients in almost the same amounts, but differing in added dietary fibre, lead to different physiological responses in diabetic subjects. Furthermore, insulin response should be considered when fibre is incorporated into the diabetic's diet.

Changes in body composition, resting energy expenditure, and thermic effect of food in short children on growth hormone therapy

The effect of growth hormone (GH) treatment on body composition, resting energy expenditure (REE), and the thermic effect of food (TEF) was studied in 10 prepubertal boys (aged 6.2 to 9.5 years, with subnormal spontaneous GH secretion during the first 6 months of treatment [0.2 IU/kg.dl]). Patients were studied before and at 2, 4, and 6 months after commencing treatment. Height and weight increased significantly during treatment (112.2 +/- 4.5 to 117.2 +/- 6.0 cm and 18.0 +/- 2.8 to 20.8 +/- 3.2 kg, respectively). Body fat percent decreased significantly (15.93% +/- 4.08% to 11.97% +/- 3.30%, P < .0002), but was not different at 4 and 6 months. Total body potassium (TBK) increased significantly (39.15 +/- 5.77 to 48.70 +/- 6.35 g, P < .001) during treatment. When correcting for the expected changes in body composition over time, height and weight were still shown to increase, fat percent decreased significantly, but TBK and mid-arm muscle circumference (MAMC) were not different from the expected values. REE increased significantly during treatment, but when it was expressed per TBK or corrected for the change in kilograms of fat-free body mass (FFBM), it increased only at 2 months and stabilized thereafter. The TEF was increased at 2 and 4 months of treatment and returned to pretreatment levels at 6 months of treatment. Substrate utilization as studied by indirect calorimetry pointed toward a significant protein-sparing effect during the first 4 months of treatment; this change tended to disappear in resting energy metabolism by 6 months of GH treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Malabsorption in infants with congenital heart disease under diuretic treatment

Intestinal absorption and its relationship to increased total body water was studied in seven infants with congenital heart disease receiving regular diuretics due to congestive heart failure. All infants and six age-matched healthy controls were studied for a 3-d period during which time all food intake was recorded, stools were collected, and total body water content (TBW) and extracellular water were measured. All the anthropometric measurements were lower in the infants with congenital heart disease compared with healthy controls. Energy and fat excretion in the stools were significantly increased in the group of patients, but when expressed as a percentage of daily caloric intake or as a percentage of the specific intake (e.g. fat excretion/fat intake x 100), no statistical differences were found. TBW as a percentage of body weight was increased in our patients compared with our controls (84.95 +/- 5.82% versus 68.65 +/- 4.60%; p = 0.01) and so was extracellular water as a percentage of predicted (200.0 +/- 18.6% versus 100.9 +/- 7.2%; p = 0.001). A positive correlation was found between energy and fat excretion as a percentage of the intake and TBW as a percentage of predicted; energy and fat malabsorption did not exceed 8% in the patients with the highest body water content (120% of predicted). It is concluded that malabsorption is not a significant factor in failure to thrive of patients with congenital heart disease who are receiving regular diuretics. Based on the significant negative correlation between excess body water and fat and calorie absorption, however, it is suggested to monitor TBW in patients who fail to gain weight.

Effect of long-term growth hormone therapy on bone age and pubertal maturation in boys with and without classic growth hormone deficiency

We evaluated the effect of growth hormone (GH) therapy on bone age, pubertal maturation and predicted adult height in two groups of boys treated for 4 years: 40 growth hormone-deficient boys who had growth hormone response to provocative stimulation < 10 micrograms/L (GHD group) and 43 boys whose stimulated growth hormone > or = 10 micrograms/L (group with neurosecretory dysfunction (NSD)). All patients had a subnormal integrated concentration of growth hormone < or = 3.2 micrograms/L, height < -2 SD, growth velocity < 4.5 cm/yr, and bone age < or = -2 SD for chronologic age. Patients were treated with recombinant growth hormone, 0.1 mg/kg per dose given three times a week. The pretreatment height SD of the GHD group (-3.6 +/- 1.0) was less than that of the NSD group (-2.7 +/- 0.7; p < 0.001). After 4 years of therapy, both groups had catch-up growth (GHD group to -2.0 +/- 1.3 height SD (n = 35), and NSD group to -1.4 +/- 0.7 height SD (n = 32)); the rate of height SD gain was better in patients with GHD (p < 0.01). The response to growth hormone was inversely related to pretreatment chronologic age (p < 0.001). The Tanner-Whitehouse II predicted adult height improved for both groups: +9.3 +/- 7.7 cm in the GHD group, giving an adult height SD of -0.9 +/- 1.0, and +5.4 +/- 5.5 cm in patients with NSD, for an adult height SD if -0.8 +/- 0.7. Testosterone levels became higher in the NSD group after 2 years and remained higher at year 4. We conclude that patients respond favorably to growth hormone therapy and in a manner similar to patients with GHD. Initiation of therapy at a younger age gives a greater improvement in gained height and predicted adult height.

Increased neutrophil chemiluminescence production in patients with cystic fibrosis

Increased free radical production has been suggested as a possible mechanism involved in lung deterioration of patients with cystic fibrosis (CF). Vitamins A and E are known to be involved in the defense mechanism preventing damage caused by free radicals. Both vitamins are fat-soluble and are therefore malabsorbed in patients with CF. We hypothesized that low concentrations of vitamins A and E may be involved in the increased free radical production of these patients. Neutrophils' chemiluminescence and superoxide and hydrogen peroxide production were examined in 11 patients with CF aged 4 to 14 years, and 10 age-matched healthy controls. All our patients were on prolonged supplementation with vitamins A and E, but the control group was not supplemented. Serum vitamins A and E levels and neutrophil vitamin E concentrations were examined concomitantly. Chemiluminescence production was increased 10 minutes after neutrophil stimulation by phorbol myristate acetate (PMA) as compared with that in normals (20,400 +/- 9,463 v 11,990 +/- 3,778 cpm, P < .03). No difference was found in superoxide or hydrogen peroxide production between CF patients and controls. Serum vitamin A levels were significantly higher in CF patients compared with healthy controls (0.641 +/- 0.049 v 0.398 +/- 0.038 mg/L, P < .04) and so were vitamin E levels (13.94 +/- 2.25 v 5.64 +/- 1.15 mg/L, P < .05). Neutrophil vitamin E concentrations were higher in CF patients compared with healthy controls (70.8 +/- 26.0 v 23.6 +/- 9.0 micrograms/10(6) cells). We conclude that neutrophils from CF patients exhibit increased chemiluminescence activity not related to increased free radical production or fat-soluble vitamin deficiency.

Changes in body composition of children with chronic renal failure during growth hormone treatment

Growth hormone (GH) has different known metabolic effects, among which are lipolysis and anabolic action. We have studied the changes in body composition of children with chronic renal failure (CRF) after 1 year of daily treatment with GH. Body fat percentage and fat body mass (FBM) were derived from four site skinfold measurements; lean body mass (LBM) from total body potassium (TBK) and mid-arm muscle circumference (MAMC); bone mineral density (BMD) was measured by dual photon absorptiometry. GH treatment had a positive effect on weight, height and MAMC, but no effect on LBM (as reflected by TBK), FBM and BMD. Z-scores were derived in order to compare subjects with a normal population. While no significant change in z-score was noticed for weight, height, MAMC, FBM and BMD, TBK decreased during treatment. We conclude that GH therapy does not ultimately increase LBM in CRF patients compared with other GH-treated groups.

Superoxide production during refeeding in patients with anorexia nervosa

The effect of undernutrition and refeeding on superoxide production by polymorphonuclear cells (PMN) was studied in 11 girls suffering from anorexia nervosa (AN) and 17 age-matched, normal, healthy, control subjects. Superoxide anion production by PMNs from undernourished AN patients was comparable to normal, while a significant decrease in this function was observed during the initial period of refeeding. After a more extended period of refeeding, superoxide production by PMNs from AN patients increased and gradually returned toward normal values. Superoxide production correlated with length of the refeeding period (RF), weight as a percentage of ideal weight for height (W/H%), and rate of weight gain (WG). These results imply that a variety of physiological parameters, including susceptibility to infection, may be altered by refeeding undernourished patients.

Evidence for genetic determination in human twins of olfactory thresholds for a standard odorant

Olfactory thresholds for four odorants were determined in groups of monozygotic and dizygotic human twins. Odorants were presented in an ascending dilution series in odorless solvent, using a three-way forced choice method. For two of the tested odorants, 5 alpha-androst-16-en-3-one and isoamyl acetate, the thresholds showed a strong genetic component. This was demonstrated by respective values of 0.78 and 0.73 for the intraclass correlation difference, and of z = 3.69 and z = 2.71 in a within-pair difference analysis. The results for isoamyl acetate are novel, and suggest that genetic polymorphism in the affinity of odorant receptor proteins contributes to the (nearly normal) threshold distribution for this odorant.

Glycemic indices of various foods given to pregnant diabetic subjects

The applicability of the glycemic index concept in pregnancy has not been established. The postprandial glucose curves were measured for nine foods (glucose, bread, raisins, dates, sweet corn, bananas, oranges, spaghetti, and green peas) in 28 gestational diabetic subjects. Uniform glycemic indices were observed for each food, similar to those reported by others in nonpregnant subjects. Postprandial glucose levels reached their peak later after glucose and bread ingestion than after the remaining seven foods. These results demonstrate that despite known changes in gastrointestinal function in pregnancy, glycemic indices are uniform after the ingestion of foods. Pregnancy does not appear to alter the glycemic indices of the foods tested.