Effects of insulin-like growth factor I treatment on the molecular distribution of insulin-like growth factors among different binding proteins

The molecular distribution of insulin-like growth factor I (IGF-I) and IGF-II among the IGF binding proteins (IGFBPs) was studied before and during IGF-I therapy in Ecuadorean adults with growth hormone receptor deficiency (GHRD). Of the total circulating IGF-I and IGF-II, 70% was carried by the 150 kDa complex in normal subjects, while in patients with GHRD, 50% of serum IGF-I, but only 30–35% of serum IGF-II, was measured within the 150 kDa IGFBP-3 region. Administration of IGF-I altered the concentration of IGF-I and IGF-II, although the percentage of total IGF measured within each IGFBP region was not affected, as the increase in IGF-I and the decrease in IGF-II were proportional. Similarly, serum concentrations of IGFBP-3 and the acid-labile subunit, measured by radioimmunoassay, were unaltered. Thus, administration of IGF-I to patients with GHRD was unable to correct the aberrant distribution of IGFs among the IGFBPs.     

Vascular air embolism: A rare complication of nasal CPAP

Abstract: A preterm infant developed bilateral tension pneumothoraces and extensive vascular air embolism 6 h after being commenced on nasal continuous positive airway pressure (CPAP). Neonatal clinicians should be aware that catastrophic vascular air embolism could occur in infants receiving nasal CPAP, a modality of respiratory support conventionally considered non-invasive and 'safe'.     

Whole body bone mineral content in healthy children and adolescents

Data from healthy children are needed to evaluate bone mineralisation during childhood. Whole body bone mineral content (BMC) and bone area were examined by dual energy x ray absorptiometry (Hologic 1000/W) in healthy girls (n = 201) and boys (n = 142) aged 5-19 years. Centile curves for bone area for age, BMC for age, bone area for height, and BMC for bone area were constructed using the LMS method. Bone mineral density calculated as BMC/bone area is not useful in children as it is significantly influenced by bone size. Instead, it is proposed that bone mineralisation is assessed in three steps: height for age, bone area for height, and BMC for bone area. These three steps correspond to three different causes of reduced bone mass: short bones, narrow bones, and light bones.     

Posture testing (posturography) in the diagnosis of peripheral vestibular pathology

In patients with peripheral vestibular deficiencies, the testing of posture or "posturography" can give specific information about any compensation obtained in the vestibulospinal reflex (VSR). We have used the statokinesimetric parameter of length in this study. Nearly 50% of the patients with unilateral vestibular hypofunction as well as those patients with paroxysmal positional vertigo (PPV) show abnormal results. These findings indicate deficient compensation at the vestibulospinal level, which is independent of any compensation already achieved at the vestibulo-ocular level. The tests used for the latter, such as positioning and rotational tests, are unable to provide information about the degree of compensation reached in the VSR. The examinations used in the different modalities of sensory interaction can show the presence of influences of ocular fixation and changes of head position. We have observed three types of deviant interaction. Our posturographic data have allowed us to assess functional situations in a more precise way. Any rehabilitation exercises used should be adapted according to these data.     

Coupling between spontaneous pupillary fluctuations and brain activity relates to inattentiveness

Autonomic activity in neurological and psychiatric disorders is often dysregulated, particularly in the context of attentional behaviors. This suggests that interplay between the autonomic nervous system and aspects of the central nervous system subserving attention may be disrupted in these conditions. Better understanding these interactions and their relationship with individual variation in attentional behaviors could facilitate development of mechanistic biomarkers. We identified brain regions defined by trait‐sensitive central–autonomic coupling as a first step in this process. As spontaneous neural activity measured during the resting state is sensitive to phenotypic variability, unconfounded by task performance, we examined whether spontaneous fluctuations in brain activity and an autonomic measure, pupil diameter, were coupled during the resting state, and whether that coupling predicted individual differences in attentional behavior. By employing concurrent pupillometry and fMRI during the resting state, we observed positive coupling in regions comprising cingulo‐opercular, default mode, and fronto‐parietal networks, as well as negative coupling with visual and sensorimotor regions. Individuals less prone to distractibility in everyday behavior demonstrated stronger positive coupling in cingulo‐opercular regions often associated with sympathetic activity. Overall, our results suggest that individuals less prone to distractibility have tighter intrinsic coordination between specific brain areas and autonomic systems, which may enable adaptive autonomic shifts in response to salient environmental cues. These results suggest that incorporating autonomic indices in resting‐state studies should be useful in the search for biomarkers for neurological and psychiatric disorders.     

Telomerase activation in normal B lymphocytes and non-Hodgkin's lymphomas

Activation of telomerase seems to be a prerequisite for immortalization and is found in permanent cell lines and most malignant tumors. Normal somatic cells are generally telomerase negative, except for bone marrow stem cells. Weak activity is also present in peripheral blood cells. In the present study strong telomerase activity was demonstrated in vivo in normal mature cells of the immune system, as well as in malignant lymphomas. Benign lymph nodes had lower telomerase activity than benign tonsils, which exhibited intermediate to high activity comparable with findings in malignant lymphomas. In benign tonsils the activity seemed to be restricted to germinal center B cells. In benign lymphoid tissues telomerase activity correlated with B-cell numbers and cell proliferation, but this was not observed in the lymphoma group. High- grade lymphomas exhibited higher levels of telomerase compared with low- grade cases. The data showed that in vivo activation of telomerase is a characteristic feature of germinal center B cells. Different signals for activation of telomerase are likely to exist, one of them being immune stimulation. The data suggest that telomerase activity in malignant lymphomas can be explained by an "induction and retention" model, ie, transformation occurs in a normal, mature B cell with reactivated telomerase, which is retained in the neoplastic clone.     

Differential responses of granulosa cells from small and large follicles to follicle stimulating hormone (FSH) during the menstrual cycle and acyclicity: effects of tumour necrosis factor-alpha

This study determined effects of follicle stimulating hormone (FSH) alone and in combination with tumour necrosis factor (TNF), on granulosa cells from small (5-10 mm diameter) and large (>10-25 mm) follicles during follicular and luteal phases of the cycle and during periods of acyclicity. Granulosa cells were collected from ovaries of premenopausal women undergoing oophorectomy. The cells were cultured with human FSH (2 ng/ml) and testosterone (1 microM) in the presence or absence of human TNF-alpha (20 ng/ml). Media were removed at 48 and 96 h after culture and progesterone, oestradiol and cAMP in media were measured by radioimmunoassays. FSH stimulated the accumulation of oestradiol from granulosa cells of small follicles during the follicular and luteal phases but not during acyclicity; and TNF reduced oestradiol accumulation in the presence of FSH. Interestingly, in granulosa cells from small follicles, progesterone and cAMP secretion increased in response to FSH and neither was affected by TNF. Thus, TNF specifically inhibited the conversion of testosterone to oestradiol in granulosa cells from small follicles. FSH stimulated oestradiol production by granulosa cells of large follicles obtained only during the follicular phase of the cycle and TNF inhibited the FSH-induced oestradiol secretion. Granulosa cells obtained from large follicles during the luteal phase and during acyclicity did not accumulate oestradiol in response to FSH. However, FSH increased progesterone and cAMP secretion by granulosa cells obtained from large follicles during the follicular and luteal phases. During the luteal phase alone, TNF in combination with FSH increased progesterone accumulation above that of FSH alone. FSH did not increase progesterone, oestradiol or cAMP secretion by granulosa cells obtained from large follicles during acyclicity. Thus, FSH increases progesterone, oestradiol and cAMP secretion by granulosa cells of small follicles during the follicular and luteal phases and TNF appears to inhibit FSH-induced oestradiol secretion specifically in those cells. In large follicles, FSH- stimulated granulosa cell secretion of oestradiol is limited to the follicular phase and this effect can be inhibited by TNF. In addition, when granulosa cells of large follicles do not increase oestradiol secretion in response to FSH, TNF stimulates progesterone secretion.      

Emotional adjustment and concerns of Korean mothers of premature infants

This study describes the emotional adjustment and concerns of 50 Korean mothers of premature infants from hospitalization through six weeks after discharge. Five themes emerged: self-blame, concern about the infant, reluctance to express negatives, fear of stigmatizing responses to the infant by others, and delayed joy in mothering. Three Korean cultural beliefs influenced mothers' responses to premature birth: maternal responsibility for infant outcomes, negative thoughts can lead to negative consequences, and stigmatization of prematurity. Results identify specific ways caregivers in Korea and other countries can provide culturally appropriate support for Korean mothers experiencing a premature birth.     

Vestibular compensation evaluated by rotation tests and posturography

In patients with unilateral vestibular hypofunction (UVH), compensation plays an indispensable role in reorganizing and returning to normal the vestibulo-ocular reflex (VOR) and the vestibulospinal reflex (VSR). These compensatory and adaptive processes, however, may have an independent course because the results for VOR are nontransferable to VSR. Discordance between results of rotation tests (evaluating the compensation for the VOR) and posturographic (PG) results (evaluating compensation for the VSR) are observed in 50% of the patients with UVH. The complaint of "instability" shows correlation with abnormal PG data. Accordingly, a thorough evaluation of a patient with UVH has to include information about the VSR as it can be provided by PG.     

Acute spinal cord injury: MR imaging at 1.5 T

Thirty-seven magnetic resonance (MR) imaging studies were performed with a 1.5-T magnet and surface coils in 27 patients with suspected spinal cord injuries. Imaging was performed 1 day to 6 weeks after injury. Cord abnormalities were seen with MR in 19 patients, while skeletal and/or ligamentous injuries were seen in 21 (78%). Three types of MR signal patterns were seen in association with cord injuries. Acute intraspinal hemorrhage was seen in five patients with cord injuries and demonstrated decreased signal intensity on T2-weighted images obtained within 24 hours of injury. Cord edema and contusion had high signal intensity on T2-weighted images and were observed in 12 cases with cord injury. Neurologic recovery, determined in 16 patients, was insignificant in patients with intraspinal hemorrhage; however, patients with cord edema or contusion recovered significant neurologic function. MR at 1.5 T is extremely useful in the diagnosis of acute cord injury and also demonstrates potential in predicting neurologic recovery.