The Trans-Gompertz Function: An Alternative to the Logistic Growth Function with Faster Growth.

The growth characteristics of the recently derived Trans-Gompertz function are compared to those of the Generalized Logistic function. Both functions are defined by one shaping parameter and one rate parameter. The functions are matched at a specified point on the growth curve by equating both the first and second derivatives. Analysis shows that the matched Trans-Gompertz function will have grown at a faster rate with a larger inflection point ratio.

Trans-theta logistics: a new family of population growth sigmoid functions.

Sigmoid functions have been applied in many areas to model self limited population growth. The most popular functions; General Logistic (GL), General von Bertalanffy (GV), and Gompertz (G), comprise a family of functions called Theta Logistic ([Formula: see text] L). Previously, we introduced a simple model of tumor cell population dynamics which provided a unifying foundation for these functions. In the model the total population (N) is divided into reproducing (P) and non-reproducing/quiescent (Q) sub-populations. The modes of the rate of change of ratio P/N was shown to produce GL, GV or G growth. We now generalize the population dynamics model and extend the possible modes of the P/N rate of change. We produce a new family of sigmoid growth functions, Trans-General Logistic (TGL), Trans-General von Bertalanffy (TGV) and Trans-Gompertz (TG)), which as a group we have named Trans-Theta Logistic (T [Formula: see text] L) since they exist when the [Formula: see text] L are translated from a two parameter into a three parameter phase space. Additionally, the model produces a new trigonometric based sigmoid (TS). The [Formula: see text] L sigmoids have an inflection point size fixed by a single parameter and an inflection age fixed by both of the defining parameters. T [Formula: see text] L and TS sigmoids have an inflection point size defined by two parameters in bounding relationships and inflection point age defined by three parameters (two bounded). While the Theta Logistic sigmoids provided flexibility in defining the inflection point size, the Trans-Theta Logistic sigmoids provide flexibility in defining the inflection point size and age. By matching the slopes at the inflection points we compare the range of values of inflection point age for T [Formula: see text] L versus [Formula: see text] L for model growth curves.

KChIP1 modulation of Kv4.3-mediated A-type K(+) currents and repetitive firing in hippocampal interneurons.

Neuronal A-type K(+) channels regulate action potential waveform, back-propagation and firing frequency. In hippocampal CA1 interneurons located at the stratum lacunosum-moleculare/radiatum junction (LM/RAD), Kv4.3 mediates A-type K(+) currents and a Kv4 ß-subunit of the Kv channel interacting protein (KChIP) family, KChIP1, appears specifically expressed in these cells. However, the functional role of this accessory subunit in A-type K(+) currents and interneuron excitability remains largely unknown. Thus, first we studied KChIP1 and Kv4.3 channel interactions in human embryonic kidney 293 (HEK293) cells and determined that KChIP1 coexpression modulated the biophysical properties of Kv4.3 A-type currents (faster recovery from inactivation, leftward shift of activation curve, faster rise time and slower decay) and this modulation was selectively prevented by KChIP1 short interfering RNA (siRNA) knockdown. Next, we evaluated the effects of KChIP1 down-regulation by siRNA on A-type K(+) currents in LM/RAD interneurons in slice cultures. Recovery from inactivation of A-type K(+) currents was slower after KChIP1 down-regulation but other properties were unchanged. In addition, down-regulation of KChIP1 levels did not affect action potential waveform and firing, but increased firing frequency during suprathreshold depolarizations, indicating that KChIP1 regulates interneuron excitability. The effects of KChIP1 down-regulation were cell-specific since CA1 pyramidal cells that do not express KChIP1 were unaffected. Overall, our findings suggest that KChIP1 interacts with Kv4.3 in LM/RAD interneurons, enabling faster recovery from inactivation of A-type currents and thus promoting stronger inhibitory control of firing during sustained activity.

A unified model of sigmoid tumour growth based on cell proliferation and quiescence.

OBJECTIVES: A class of sigmoid functions designated generalized von Bertalanffy, Gompertzian and generalized Logistic has been used to fit tumour growth data. Various models have been proposed to explain the biological significance and foundations of these functions. However, no model has been found to fully explain all three or the relationships between them. MATERIALS AND METHODS: We propose a simple cancer cell population dynamics model that provides a biological interpretation for these sigmoids' ability to represent tumour growth. RESULTS AND CONCLUSIONS: We show that the three sigmoids can be derived from the model and are in fact a single solution subject to the continuous variation of parameters describing the decay of the proliferation fraction and/or cell quiescence. We use the model to generate proliferation fraction profiles for each sigmoid and comment on the significance of the differences relative to cell cycle-specific and non-cell cycle-specific therapies.

[The interpreter in an intercultural clinical milieu]. / L'interprète en milieu clinique interculturel.

The public's diversified language profile means that nursing practice must adjust to provide the same quality of care to all clients, no matter what language they speak. To improve quality and quantity of information exchanged in the nurse-client-interpreter triangle, the authors have investigated the type of information likely to be filtered and studied the various factors underlying the interpreter's choice to filter information. The authors also analyzed the values interpreters assign to information and the factors that form the background for filtering, including mistrust. The authors suggest adequately preparing interpreters; using interpreters' expertise; and developing an appropriate training program for intercultural interpreters to enable them to better function within health care institutions.

Diversity in the pastoral relationship: an evaluation of the helping styles inventory.

Presents an ethnographic study of practitioners' experiences of the Helping Styles Inventory (HSI). Analyzes the data from twenty-one interviews, noting helpful and limiting aspects of the HSI. Discusses implications of the research for the HSI and for ministry in general.

Autologous blood stem cell transplantation for chronic granulocytic leukaemia in transformation: a report of 47 cases.

Forty-seven patients with chromosome Philadelphia-positive (Ph1) chronic granulocytic leukaemia (CGL) in transformation underwent autologous transplantation of peripheral blood stem cells (ABSCT) collected at the original diagnosis before any treatment. They were treated with three consecutive strategies: single transplant (group I = 17 patients), double transplant (group II = 13 patients), double transplant followed by recombinant alpha interferon (group III = 17 patients). Forty-three patients were restored to a second chronic phase with a cytogenetic conversion (more than 10% Ph1-negative marrow metaphases) occurring in 14 of the 29 evaluable patients. Most patients had a recurrent transformation occurring 2-43 months after ABSCT and finally eight patients are still alive in second chronic phase 4-49 months after ABSCT (median = 24 months). The actuarial median duration of second chronic phase was 3 months, 10 months and 18 months for group I, group II and group III patients (P less than 0.0001). The encouraging results observed for group III patients prompt us to propose ABSCT for patients in chronic phase with initial prognostic factors, suggesting that recombinant alpha interferon will not be effective if administered as front-line therapy.

Relationship between patients' age, bone marrow karyotype, and outcome of induction therapy in acute myelogenous leukemia.

Bone marrow karyotypes were performed in 88 cases of adult acute myelogenous leukemia (AML) at diagnosis and classified NN (normal), AA (abnormal), and AN (mixture of normal and abnormal metaphases). A clear relationship was found between karyotype and complete remission (CR) rate: 58% CR in (NN + AN) cases; 14% CR in AA cases (P less than .009). This relationship was even stronger when only patients under 60 years of age were studied. Considering failures of induction treatment, no relationship was found between the NN/AN/AA classification and a drug resistance. In patients over 60, the worse prognosis could be explained by an inferior ability to tolerate intensive treatment.

[Verbal abilities of normal adults submitting to an aphasia linguistic protocol]. / Capacités verbales d'adultes normaux soumis à protocole linguistique de l'aphasie.

A language test protocol for aphasia in French-speaking patients was drawn up recently by workers in Toulouse and Montreal. The protocol has been applied to sixty hospitalized sciatica patients of the same age range and socio-cultural level as the average population of aphasics in our department. Only one of the normal patients passed the test without any mistakes. The number and nature of the mistakes are studied statistically in relation to age, sex and socio-cultural level.

[Partial 7q trisomy]. / Trisomie 7q partielle

A 17-month old boy is partially trisomic for 7q22 and 7q31 due to a probable insertion in the paternal chromosome 13. The phenotype of the patient is similar to that of two other patients reported in the literature.