Bifurcations in a system described by a nonlinear differential equation with delay.

Computer simulations of a nonlinear differential equation with time delay have been carried out to determine the possible steady states over a wide range of parameter values. A variety of nonlinear phenomena, including chaotic attractors and multiple coexisting attractors, are observed. Precision of the solutions is verified by means of evaluating the computational error at each time step.

Cause-specific mortality in long-term survivors of breast cancer who participated in trials of radiotherapy.

Purpose: To examine long-term cause-specific mortality in patients irradiated for breast cancer as part of a randomized clinical trial.

Patients And Methods: We studied all available information from randomized trials initiated before 1975 in which radiotherapy was the randomized option and surgery was the same for both treatment arms. Eight such trials were identified.

Localization of oxytocin receptor mRNA in the ovine uterus during the oestrous cycle and early pregnancy.

A synthetic 45-mer oligonucleotide corresponding to part of the ovine endometrial oxytocin receptor cDNA was hybridized to sections of ovine uterus collected from 40 ewes at different stages during the oestrous cycle, the first 3 weeks of pregnancy and seasonal anoestrus. The quantity of oxytocin receptor mRNA was measured as the optical density (OD) value on autoradiographs using image analysis. Message first appeared in the luminal epithelium on days 14-15 of the cycle, increasing to a peak OD of 0.

An interferon-induced Mx protein: cDNA sequence and high-level expression in the endometrium of pregnant sheep.

We have cloned a 2.4-kb cDNA containing the complete coding sequence of ovine Mx from a lambda ZAP library constructed using RNA from the endometrium of a normal sheep on day 16 of pregnancy. Ovine Mx shows 80% similarity to human MxA.

Anti-glutamate therapy in amyotrophic lateral sclerosis: a trial using lamotrigine.

Glutamate excitotoxicity is implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). We report the results of a double blind, placebo controlled, trial using 100 mg of oral daily lamotrigine (3,5-diamino-6-(2,3 dichlorophenyl)-1,2,4-triazine) which inhibits glutamate release. 67 patients were entered and at trial termination of 1.

Patients first: small hospitals in Ontario favour patient-focused care.

Is patient-focused care the model of the future? In 1993, CEOs of selected small hospitals across Ontario were asked if the patient-focused-care model is used in their facilities and, if so, to provide examples of some of the activities involved. This article presents a summary of the study's findings, discusses the model's merits and challenges for implementation, and offers several recommendations to assist hospitals contemplating the introduction of this model of health care delivery.

Changes in DNA synthesis rate in the Schwann cell lineage in vivo are correlated with the precursor--Schwann cell transition and myelination.

During the development of the rat sciatic nerve extensive proliferation of glial cells occurs, and there is a very substantial rearrangement of the cytoarchitecture as axons and Schwann cells assume relationships which lead to the formation of the myelinated and unmyelinated axons characteristic of adult nerve. The maturation of Schwann cells from Schwann cell precursors and the matching of Schwann cell numbers to axons is an important part of this process. We have therefore studied the proliferation of Schwann cell precursors and Schwann cells during the development of the rat sciatic nerve from embryonic day 14 to postnatal day 28 by combining bromodeoxyuridine injections of rats with double-label immunohistochemical techniques.

Receiver operating characteristic curve analysis in the prediction of carpal tunnel syndrome: a model for reporting electrophysiological data.

Receiver operating characteristic (ROC) curves were used to predict the risk of carpal tunnel syndrome (CTS). Patients were classified clinically as: (1) normal exam and no symptoms (169 hands); (2) having a motor and/or sensory deficit typical of CTS (115 hands); (3) having a history characteristic of CTS (156 hands); and (4) nondiagnostic symptomatology (122 hands). Electrophysiological studies consisted of median and ulnar motor, sensory, and palmar measurements.

Isolation and structure of a partial sheep oxytocin receptor cDNA and its use as a probe for northern analysis of endometrial RNA.

The polymerase chain reaction (PCR) was used to generate a 131 bp cDNA encoding part of the sheep endometrial oxytocin receptor. The nucleotide sequence of this cDNA was 93.8% identical to the human oxytocin receptor sequence in this region.

Cortical excitability in amyotrophic lateral sclerosis: a clue to pathogenesis.

Motor evoked potentials (MEPs) were recorded from selected non-wasted, non-denervated hand muscles in 40 patients with Amyotrophic Lateral Sclerosis (ALS) with both upper and lower motor neuron signs. In most the compound muscle action potential (CMAP) of the target muscle was normal. Compared to the control group, cortical threshold in ALS varied considerably and there was a significant (r2 = 0.

Angiofollicular lymphoid hyperplasia (Castleman's disease) in two mice treated with polyoma virus or urethane.

Localized angiofollicular hyperplasia, otherwise known as Castleman's disease, is described in the lymph nodes of 2 mice of different strains, one inoculated with polyoma virus at birth and the other given urethane within 24 hr of birth. A plasma cell component in the lesion, suggestive of bone marrow stem cell involvement, was present in the mouse treated with polyoma virus but absent in the mouse given intraperitoneal urethane. Dysregulated interleukin 6 has recently been reported to produce the systemic variety of angiofollicular hyperplasia in mice, but the role of this cytokine in the localized variety described in this report is not known.

Long-term results of the Manchester knee. Surface arthroplasty of the tibiofemoral joint.

Unicompartmental knee replacement is increasing in popularity. Long-term analysis of an early bi-compartment variety, the Manchester knee, therefore has relevance. One hundred fifty-six consecutive Manchester knee replacements were observed, 47 for longer than ten years.

Isometric joystick: a study of control by adolescents and young adults with cerebral palsy.

This research was undertaken to determine the best wheelchair driving method for clients with cerebral palsy who were experiencing difficulties using displacement joysticks. The hypothesis was that adolescents with cerebral palsy would perform better in a tracking task using an isometric joystick (which has no moving parts) than a displacement joystick of the type used in commercial wheelchair controllers. A series of single subject case studies was performed in which the activating force of the isometric joystick was individualised for each subject.

GAP-43 is expressed by nonmyelin-forming Schwann cells of the peripheral nervous system.

Recently it has been demonstrated that the growth-associated protein GAP-43 is not confined to neurons but is also expressed by certain central nervous system glial cells in tissue culture and in vivo. This study has extended these observations to the major class of glial cells in the peripheral nervous system, Schwann cells. Using immunohistochemical techniques, we show that GAP-43 immunoreactivity is present in Schwann cell precursors and in mature non-myelin-forming Schwann cells both in vitro and in vivo.

GAP-43 immunoreactivity is widespread in the autonomic neurons and sensory neurons of the rat.

GAP-43 is a membrane-bound phosphoprotein generally associated with axon growth during development and regeneration. Using immunohistochemical and immunoblotting techniques this study shows that GAP-43 is expressed extensively in the unperturbed adult autonomic nervous system. Strong immunoreactivity was seen in the developing and mature enteric subdivision of the autonomic nervous system and in nerves of the iris and various blood vessels.

Trophoblast interferons in early pregnancy of domestic ruminants.

A type I interferon (IFN) secreted by the trophoblast of early sheep and cow embryos is thought to be responsible for the maternal recognition of pregnancy. The expression of trophoblast IFN is tissue specific and temporally controlled. However, the isolated bovine trophoblast IFN promoter did not confer tissue specificity on the expression of a bacterial chloramphenicol acetyl transferase (CAT) reporter gene, and could not be induced by virus, unlike other type I IFNs.

Role of the oxytocin receptor in the choice between cyclicity and gestation in ruminants.

The endometrial oxytocin receptor occupies a central point in the choice between luteolysis and pregnancy in ruminants. Receptor expression determines the time at which luteolysis occurs in nonpregnant animals, and thereby determines the duration of the oestrous cycle. Inhibition of receptor expression by trophoblast interferon (IFN) blocks the process of luteal regression and leads to continued progesterone secretion and the successful growth of the conceptus.

The Scottish trial of adjuvant tamoxifen in node-negative breast cancer. Scottish Cancer Trials Breast Group.

This paper presents results, 5 years after closure, of a randomized trial comparing adjuvant with postrelapse tamoxifen in 747 women with histological node-negative breast cancer. Two hundred thirty-six disease-free patients on adjuvant therapy were secondarily randomly assigned at 5 years to stop or to continue tamoxifen until relapse. Adjuvant tamoxifen, taken for a median duration of 60 months, has significantly prolonged disease-free survival overall (P = .

Interaction between cAMP elevation, identified growth factors, and serum components in regulating Schwann cell growth.

Most previous studies on Schwann cell proliferation in vitro have used serum-containing media. This complicates the analysis of agents required for cell division since serum contains an ill-defined mixture of hormones and growth factors. Serum-free medium has therefore been used to analyse the response of Schwann cell to previously identified Schwann cell mitogens.