577 research outputs found
Bombesin and bombesin antagonists: studies in Swiss 3T3 cells and human small cell lung cancer.
Bombesins are potent growth factors for murine Swiss 3T3 cells. Using these cells in chemically defined conditions we have been able to characterise the bombesin receptor and the early signals preceding DNA synthesis. We describe two substance P analogues [DArg1, DPro2, DTrp7,9, Leu11] substance P and [DArg1, DPhe5, DTrp7,9, Leu11] substance P which competitively block the binding of bombesins to their receptor and all the events leading to mitogenesis. Bombesins are secreted by human small cell lung cancers (SCLC) and may act as autocrine growth factors for these tumours, so the development of peptide bombesin antagonists could have therapeutic implications. We demonstrate that the antagonists can reversibly inhibit the growth of SCLC in vitro, with relatively little effect on other lung tumours
Treatment of bone metastases from breast cancer with (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate (APD).
Twenty-eight patients with progressive symptomatic bone metastases from breast cancer received (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate (APD) 30 mg in 500 ml of 0.9% saline infused over 2 h every 14 days. No other systemic therapy for breast cancer was prescribed. All patients had progressed on at least one previous systemic treatment. APD was continued until the disease progressed. Patients were assessed for objective response by the UICC criteria. In addition, subjective response was determined by a pain questionnaire. Radiological evidence of bone healing with sclerosis of lytic disease (UICC partial response) was seen in 4 patients. The median duration of response was 10 months. Eleven patients had stable disease for at least 3 months (median 5 months) and 9 progressed. Symptomatic response occurred in 9 patients and 12 reported an improvement in quality of life. Treatment was tolerated well with no significant toxicity. In conclusion, long-term inhibition of bone destruction is possible with APD therapy alone and both subjective and objective responses are seen
Neural Networks Supporting Phoneme Monitoring Are Modulated by Phonology but Not Lexicality or Iconicity: Evidence From British and Swedish Sign Language
Sign languages are natural languages in the visual domain. Because they lack a written
form, they provide a sharper tool than spoken languages for investigating lexicality effects
which may be confounded by orthographic processing. In a previous study, we showed
that the neural networks supporting phoneme monitoring in deaf British Sign Language
(BSL) users are modulated by phonology but not lexicality or iconicity. In the present
study, we investigated whether this pattern generalizes to deaf Swedish Sign Language
(SSL) users. British and SSLs have a largely overlapping phoneme inventory but are
mutually unintelligible because lexical overlap is small. This is important because it means
that even when signs lexicalized in BSL are unintelligible to users of SSL they are usually
still phonologically acceptable. During fMRI scanning, deaf users of the two different sign
languages monitored signs that were lexicalized in either one or both of those languages
for phonologically contrastive elements. Neural activation patterns relating to different
linguistic levels of processing were similar across SLs; in particular, we found no effect of
lexicality, supporting the notion that apparent lexicality effects on sublexical processing
of speech may be driven by orthographic strategies. As expected, we found an effect of
phonology but not iconicity. Further, there was a difference in neural activation between
the two groups in a motion-processing region of the left occipital cortex, possibly driven
by cultural differences, such as education. Importantly, this difference was not modulated
by the linguistic characteristics of the material, underscoring the robustness of the neural
activation patterns relating to different linguistic levels of processing
Aging and memory effects in beta-hydrochinone-clathrate
The out-of-equilibrium low-frequency complex susceptibility of the
orientational glass methanol(73%)-beta-hydrochinone-clathrate is studied using
temperature-stop protocols in aging experiments . Although the material does
not have a sharp glass transition aging effects including rejuvenation and
memory are found at low temperatures. However, they turn out to be much weaker,
however, than in conventional magnetic spin glasses.Comment: 5 pages RevTeX, 6 eps-figures include
Development of coordination and muscular fitness in children and adolescents with parent-reported ADHD in the German longitudinal MoMo Study
This study examined the development of muscular fitness and coordination in children and adolescents with and without attention deficit hyperactivity disorder (ADHD) over a period of 11 years. Data was collected in three measurement waves as part of the longitudinal, representative Motorik-Modul (MoMo) study in Germany (2003–2006, 2009–2012, 2014–2017). The overall sample comprised 2988 participants (253 with ADHD, 65% males; 2735 non-ADHD, 47% males; mean age 9 years). Structural equation modeling was conducted, and the estimated models had a good fit. No differences in muscular fitness were observed between participants with and without ADHD. Participants with ADHD had a lower coordinative performance at first measurement than those without ADHD. The difference in coordinative performance persisted throughout the study period
Theory of Scanning Tunneling Spectroscopy of a Magnetic Adatom on a Metallic Surface
A comprehensive theory is presented for the voltage, temperature, and spatial
dependence of the tunneling current between a scanning tunneling microscope
(STM) tip and a metallic surface with an individual magnetic adatom. Modeling
the adatom by a nondegenerate Anderson impurity, a general expression is
derived for a weak tunneling current in terms of the dressed impurity Green
function, the impurity-free surface Green function, and the tunneling matrix
elements. This generalizes Fano's analysis to the interacting case. The
differential-conductance lineshapes seen in recent STM experiments with the tip
directly over the magnetic adatom are reproduced within our model, as is the
rapid decay, \sim 10\AA, of the low-bias structure as one moves the tip away
from the adatom. With our simple model for the electronic structure of the
surface, there is no dip in the differential conductance at approximately one
lattice spacing from the magnetic adatom, but rather we see a resonant
enhancement. The formalism for tunneling into small clusters of magnetic
adatoms is developed.Comment: 12 pages, 9 figures; to appear in Phys. Rev.
Phase II trial of temozolomide in low-grade non-Hodgkin's lymphoma.
Temozolomide, an imidazotetrazine derivative, was given to 18 patients with low-grade non-Hodgkin's lymphoma (NHL) at a dose of 750 mg m-2 orally, divided over five consecutive days, escalated to 1000 mg m-2 over 5 days (i.e. 200 mg m-2 day-1) if no significant myelosuppression was noted at day 22 of the 28 day cycle. Fifty-six treatment cycles were given to 18 patients. The drug was well tolerated. Only one partial tumour response was documented. The patients were heavily pretreated but had chemoresponsive disease, as shown by a response rate of 69% among 13 patients who went on to receive alternative cytotoxic regimens. We conclude that temozolomide given in this schedule is inactive in previously treated low-grade NHL
Edible crabs “Go West”: migrations and incubation cycle of Cancer pagurus revealed by electronic tags
Crustaceans are key components of marine ecosystems which, like other exploited marine taxa, show seasonable patterns of distribution and activity, with consequences for their availability to capture by targeted fisheries. Despite concerns over the sustainability of crab fisheries worldwide, difficulties in observing crabs’ behaviour over their annual cycles, and the timings and durations of reproduction, remain poorly understood. From the release of 128 mature female edible crabs tagged with electronic data storage tags (DSTs), we demonstrate predominantly westward migration in the English Channel. Eastern Channel crabs migrated further than western Channel crabs, while crabs released outside the Channel showed little or no migration. Individual migrations were punctuated by a 7-month hiatus, when crabs remained stationary, coincident with the main period of crab spawning and egg incubation. Incubation commenced earlier in the west, from late October onwards, and brooding locations, determined using tidal geolocation, occurred throughout the species range. With an overall return rate of 34%, our results demonstrate that previous reluctance to tag crabs with relatively high-cost DSTs for fear of loss following moulting is unfounded, and that DSTs can generate precise information with regards life-history metrics that would be unachievable using other conventional means
The acquisition of Sign Language: The impact of phonetic complexity on phonology
Research into the effect of phonetic complexity on phonological acquisition has a long history in spoken languages. This paper considers the effect of phonetics on phonological development in a signed language. We report on an experiment in which nonword-repetition methodology was adapted so as to examine in a systematic way how phonetic complexity in two phonological parameters of signed languages — handshape and movement — affects the perception and articulation of signs. Ninety-one Deaf children aged 3–11 acquiring British Sign Language (BSL) and 46 hearing nonsigners aged 6–11 repeated a set of 40 nonsense signs. For Deaf children, repetition accuracy improved with age, correlated with wider BSL abilities, and was lowest for signs that were phonetically complex. Repetition accuracy was correlated with fine motor skills for the youngest children. Despite their lower repetition accuracy, the hearing group were similarly affected by phonetic complexity, suggesting that common visual and motoric factors are at play when processing linguistic information in the visuo-gestural modality
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