'The risks of playing it safe': a prospective longitudinal study of response to reward in the adolescent offspring of depressed parents.

BACKGROUND: Alterations in reward processing may represent an early vulnerability factor for the development of depressive disorder. Depression in adults is associated with reward hyposensitivity and diminished reward seeking may also be a feature of depression in children and adolescents. We examined the role of reward responding in predicting depressive symptoms, functional impairment and new-onset depressive disorder over time in the adolescent offspring of depressed parents. In addition, we examined group differences in reward responding between currently depressed adolescents, psychiatric and healthy controls, and also cross-sectional associations between reward responding and measures of positive social/environmental functioning. Method We conducted a 1-year longitudinal study of adolescents at familial risk for depression (n = 197; age range 10-18 years). Reward responding and self-reported social/environmental functioning were assessed at baseline. Clinical interviews determined diagnostic status at baseline and at follow-up. Reports of depressive symptoms and functional impairment were also obtained. RESULTS: Low reward seeking predicted depressive symptoms and new-onset depressive disorder at the 1-year follow-up in individuals free from depressive disorder at baseline, independently of baseline depressive symptoms. Reduced reward seeking also predicted functional impairment. Adolescents with current depressive disorder were less reward seeking (i.e. bet less at favourable odds) than adolescents free from psychopathology and those with externalizing disorders. Reward seeking showed positive associations with social and environmental functioning (extra-curricular activities, humour, friendships) and was negatively associated with anhedonia. There were no group differences in impulsivity, decision making or psychomotor slowing. CONCLUSIONS: Reward seeking predicts depression severity and onset in adolescents at elevated risk of depression. Adaptive reward responses may be amenable to change through modification of existing preventive psychological interventions.

Understanding and controlling organic-inorganic interfaces in mesostructured hybrid photovoltaic materials.

The chemical compositions and structures of organic-inorganic interfaces in mesostructurally ordered conjugated polymer-titania nanocomposites are shown to have a predominant influence on their photovoltaic properties. Such interfaces can be controlled by using surfactant structure-directing agents (SDAs) with different architectures and molecular weights to promote contact between the highly hydrophobic electron-donating conjugated polymer species and hydrophilic electron-accepting titania frameworks. A combination of small-angle X-ray scattering (SAXS), scanning and transmission electron microscopy (SEM, TEM), and solid-state NMR spectroscopy yields insights on the compositions, structures, and distributions of inorganic and organic species within the materials over multiple length scales. Two-dimensional NMR analyses establish the molecular-level interactions between the different SDA blocks, the conjugated polymer, and the titania framework, which are correlated with steady-state and time-resolved photoluminescence measurements of the photoexcitation dynamics of the conjugated polymer and macroscopic photocurrent generation in photovoltaic devices. Molecular understanding of the compositions and chemical interactions at organic-inorganic interfaces are shown to enable the design, synthesis, and control of the photovoltaic properties of hybrid functional materials.

Strongly bound citrate stabilizes the apatite nanocrystals in bone.

Nanocrystals of apatitic calcium phosphate impart the organic-inorganic nanocomposite in bone with favorable mechanical properties. So far, the factors preventing crystal growth beyond the favorable thickness of ca. 3 nm have not been identified. Here we show that the apatite surfaces are studded with strongly bound citrate molecules, whose signals have been identified unambiguously by multinuclear magnetic resonance (NMR) analysis. NMR reveals that bound citrate accounts for 5.5 wt% of the organic matter in bone and covers apatite at a density of about 1 molecule per (2 nm)(2), with its three carboxylate groups at distances of 0.3 to 0.45 nm from the apatite surface. Bound citrate is highly conserved, being found in fish, avian, and mammalian bone, which indicates its critical role in interfering with crystal thickening and stabilizing the apatite nanocrystals in bone.

Unlinked elbow arthroplasty as primary treatment for fractures of the distal humerus.

This study reviews our experience with primary total elbow arthroplasty in the management of acute distal humeral fractures by use of the iBP unlinked elbow prosthesis. We followed up 9 elbows in 9 patients (including 2 with rheumatoid arthritis), with a mean age of 73 years, for a mean of 3.5 years. Functional outcome was assessed with the Mayo Elbow Performance Score and the recently developed Liverpool Elbow Score. Clinical examination and radiologic assessment were performed by an independent surgeon. All elbows were stable at the latest follow-up examination, all patients were able to perform daily activities, and pain relief was satisfactory. The median value for the Mayo Elbow Performance Score was 95 (range, 65-100). This is the first report of the use of an unlinked prosthesis for the treatment of distal humeral fractures. Our results show that this method of treatment provides a reliable and effective way of dealing with these very difficult fractures when internal fixation is not a viable option.

A new NMR method for determining the particle thickness in nanocomposites, using T2,H-selective X{1H} recoupling.

A new nuclear magnetic resonance approach for characterizing the thickness of phosphate, silicate, carbonate, and other nanoparticles in organic-inorganic nanocomposites is presented. The particle thickness is probed using the strongly distant-dependent dipolar couplings between the abundant protons in the organic phase and X nuclei (31P, 29Si, 13C, 27Al, 23Na, etc.) in the inorganic phase. This approach requires pulse sequences with heteronuclear dephasing only by the polymer or surface protons that experience strong homonuclear interactions, but not by dispersed OH or water protons in the inorganic phase, which have long transverse relaxation times T2,H. This goal is achieved by heteronuclear recoupling with dephasing by strong homonuclear interactions of protons (HARDSHIP). The pulse sequence alternates heteronuclear recoupling for approximately 0.15 ms with periods of homonuclear dipolar dephasing that are flanked by canceling 90 degrees pulses. The heteronuclear evolution of the long-T2,H protons is refocused within two recoupling periods, so that 1H spin diffusion cannot significantly dephase these coherences. For the short-T2,H protons of a relatively immobile organic matrix, the heteronuclear dephasing rate depends simply on the heteronuclear second moment. Homonuclear interactions do not affect the dephasing, even though no homonuclear decoupling is applied, because long-range 1H-X dipolar couplings approximately commute with short-range 1H-1H couplings, and heteronuclear recoupling periods are relatively short. This is shown in a detailed analysis based on interaction representations. The algorithm for simulating the dephasing data is described. The new method is demonstrated on a clay-polymer nanocomposite, diamond nanocrystals with protonated surfaces, and the bioapatite-collagen nanocomposite in bone, as well as pure clay and hydroxyapatite. The diameters of the nanoparticles in these materials range between 1 and 5 nm. Simulations show that spherical particles of up to 10 nm diameter can be characterized quite easily.

Development and validation of an elbow score.

OBJECTIVES: Few of the questionnaires available for evaluating the function and clinical state of the elbow have been validated. An ideal score would be consistent, sensitive, reliable and elbow-specific, incorporating both patient perception and clinician assessment. This was our aim. METHODS: Items were generated using 25 patients and expert opinion, and reduced using 25 new patients to yield a nine-item patient questionnaire and a six-item clinical evaluation (of strength, motion and ulnar nerve involvement). This was validated using 63 new patients (of whom 28 were studied twice without therapy and 18 were studied again after appropriate surgery). RESULTS: The test-retest reliability coefficient of determination (R2 = 0.93) and internal consistency (Cronbach's alpha = 0.98) were both good. Convergent validity was attested by good correlations with other scores, the Disabilities of Arm, Shoulder and Hand Questionnaire (DASH) and the Nottingham Health Profile (NHP) (physical) (R2 = 0.62 and 0.29, P < 0.0005). Sensitivity to change was demonstrated by correlating preoperative-postoperative changes to those in DASH and NHP (physical) (R2 = 0.50 and 0.27, P < 0.04). CONCLUSION: This is a reliable, internally consistent score, correlating well with other, non-elbow specific scores and sensitive to change on treatment.

Partial nephrectomy in cystic partially differentiated nephroblastoma.

Cystic partially differentiated nephroblastoma (CPDN) is an uncommon renal neoplasm in children. It is now recognized as a tumor with low but definite malignant potential. The authors report a patient that was treated with partial nephrectomy and chemotherapy with successful outcome. The literature on CPDN is briefly discussed.

Lymphocyte glutathione levels in acute leukemia.

The current interest in the clinical significance of the glutathione estimation in leukemia is due to its widespread effect on the cell constituent and cell function of the hematopoietic system. It helps and protects the cells against free radicals and reactive oxygen products. The present study was conducted to estimate glutathione levels in lymphocytes of 20 patients with acute leukemia before and after chemotherapy to observe the relation of glutathione level to response to chemotherapy. Twenty age and sex matched healthy volunteers served as control. In acute myeloid leukemia, the levels were almost double than that of controls (P<0.001). In acute lymphoid leukemia they were 2.5 times of the control. Lymphocyte glutathione levels was higher in active phase of disease than in remission. Lymphocyte glutathione level could act as a marker of leukemic activity and may help to predict onset of relapse. But, it is not only the determinant of response to chemotherapy.

Characteristics of bladder leiomyoma as noted on magnetic resonance imaging.

Leiomyoma of the bladder is a rare benign mesenchymal tumor that can be evaluated preoperatively with magnetic resonance imaging. Small tumors that appear to be leiomyomas on magnetic resonance imaging can be treated conservatively with transurethral resection.

Fundamentals course for 1st-year radiology residents.

RATIONALE AND OBJECTIVES: The authors set out to provide 1st-year residents with basic knowledge to make conferences more useful, to make their knowledge more uniform, and to assess their competency to begin night call. MATERIALS AND METHODS: Faculty taught three afternoon sessions a week in subspecialty areas of radiology, including physics, during the 1st 6 months of residency. Material selected was believed to be essential for the understanding of that subspecialty's didactic lecture series. Emphasis was also placed on diagnoses residents would be expected to make once they began taking night call. Material was presented through lectures, images, and unknown cases. An examination was administered at the end of the course. Residents were allowed to begin night call only after completing the course and passing the final examination. RESULTS: All 1st-year residents completed the course and passed the examination. Their scores ranged from 70% to 83.3%. CONCLUSION: Residents liked the course and reported feeling ready to begin call. Faculty reported the residents who completed the course were more knowledgeable prior to formal rotations than residents from previous years who had not taken the course.

Effects of peanut butter on ruminating.

Barton and Barton (1985) reported that supplementary peanut butter reduced rates of ruminating of 4 children with mental retardation and hypothesized that the effect was due to its thick, sticky consistency. We further examined the effects of peanut butter with 5 subjects with mental retardation by independently manipulating the caloric density versus the consistency associated with peanut butter. Results showed an inverse relation between rates of ruminating and amount of peanut butter consumed. However, this effect appeared to be primarily due to an increase in calories. A weaker and less consistent effect was ascribed to the consistency of peanut butter.

Effects of caloric level on ruminating.

A series of recent studies has shown that a number of dietary variables affect ruminative behavior in institutionalized retarded persons. This experiment extends an earlier study that examined the influence of the caloric level of the diet on the frequency of ruminating. Subjects consumed regular portions of food that varied between phases from normal to high caloric levels. The data show a clear but modest inverse relation between the caloric value of the diet and the rates of postmeal ruminating.

Plasma ferritin in the assessment of iron status of Indian infants.

In order to assess the iron nutritional status of infants, plasma ferritin levels were measured in the infants and children at different time intervals till two years of age from two different socio economic groups. While ferritin levels at 3-4 months age were significantly higher in upper income group infants, levels were almost similar in the subsequent infancy between the two income groups. A close correlation was seen between ferritin levels of mothers and infants at 1-3 months of age (p less than 0.001). Prenatal iron supplements (oral or parenteral) resulted in higher ferritin levels at 4-6 months age as compared to placebo group. While the infants born to mothers receiving parenteral iron did not show any evidence of iron deficiency (serum ferritin levels less than 12 ng/ml), 23.5 and 25.0% of infants in oral iron and placebo group had evidence of iron deficiency between 6-12 months. Thus it would appear that improving the iron status of mothers during pregnancy will have significant impact on the iron status of breast fed infants till 6 months.

Feasibility of parenteral iron therapy as a field approach for management of pregnancy anaemia.

The feasibility of parenteral iron administration for treatment of pregnancy anaemia, in field conditions was investigated. High reaction rates were observed (30-40%) with either intramuscular (im) or intravenous (iv) iron-dextran complex (test dose). Mothers with lower body weight had higher reaction rates with both im or iv iron-dextran complex. In pregnancy induced hypertension (PIH) the reaction rate was significantly lower. Our study indicates that under the existing situations of the health care system in India and the poor body weight and weight gain of Indian women during pregnancy, parenteral iron therapy for controlling anaemia may not be a feasible approach, at the field level.