Phylogenetic and physiological diversity of sulphate-reducing bacteria isolated from a salt marsh sediment

Xenopus blastula cells activate different mesodermal genes as a concentration-dependent response to activin, which behaves like a morphogen. To understand how cells recognize morphogen concentration, we have bound naturally labeled activin to cells and related this to choice of gene activation. We find that the increasing occupancy of a single receptor type can cause cells to switch gene expression. Cells sense ligand concentration by the absolute number of occupied receptors per cell (100 and 300 molecules of bound activin induce Xbra and Xgsc, respectively, i.e., 2% and 6% of the total receptors) and not by a ratio of occupied to unoccupied receptors. The long duration of occupancy explains a previously described ratchet effect. Our results suggest a new concept of morphogen gradient formation and interpretation that is particularly well suited to the needs of early development.     

Circulating soluble adhesion molecules E-cadherin, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in patients with gastric cancer

The concentrations of the soluble adhesion molecules E-cadherin, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were investigated in 45 patients with gastric cancer before treatment and their correlation with clinical, histological and routine laboratory parameters was examined. Data were collected on tumour stage at presentation, presence and sites of metastatic disease, tumour pathology, survival and results of routine laboratory tests. Serum concentrations of ICAM-1 and VCAM-1 were significantly elevated in the patients with gastric cancer in comparison with the group of healthy subjects (P < 0.00001 and P < 0.0001 respectively). Increased serum concentrations of VCAM-1 were associated with locally advanced and metastatic disease whereas ICAM-1 was significantly elevated both in local and in advanced/metastatic disease. Soluble E-cadherin and E-selectin concentrations did not show any significant elevation in gastric cancer patients. Concentrations of soluble adhesion molecules showed significant correlation with each other (except E-selectin and VCAM-1) and with alkaline phosphatase. Soluble ICAM-1 and VCAM-1 were significantly associated with an elevated total white cell count. Patients with elevated VCAM-1 had significantly poorer survival in comparison with patients with normal serum levels (P = 0.0361).     

Absence of detectable human herpesvirus 8 in the semen of human immunodeficiency virus-infected men without Kaposi's sarcoma

The prevalence of human herpesvirus 8 (HHV-8)/Kaposi's sarcoma (KS)-associated herpesvirus was investigated in the semen of 99 human immunodeficiency virus (HIV)-infected men (median CD4 cell count, 357/mm3) by use of a polymerase chain reaction (PCR) assay capable of detecting <10 copies of HHV-8 DNA. Of the subjects, 95 (96%) self-identified as men who have sex with men (MSM), and 3 had a history of clinical KS. Seminal cell specimens were negative for HHV-8 in 98 subjects. None of the 26 without KS (27.1% of 96 tested) who were seropositive for HHV-8 by IFA for latency-associated nuclear antigens had HHV-8 detected in their semen. The only subject with any evidence for seminal HHV-8 DNA was seropositive for HHV-8 and had active KS. HHV-8 was detected in 10 (10.4%) of 96 peripheral blood mononuclear cell specimens. The prevalence of HHV-8 DNA by PCR in semen of HIV-infected MSM without KS is low.     

When your patient uses denial

There are may factors to consider when denial is encountered in a patient situation. Denial is a simple concept but is complicated by ego-maintaining mechanisms that denial may produce. It is important to evaluate each individual situation in order to identify suitable approaches for the situation. Denial may not be something that the nurse should take away since it can serve an important balancing function between depression and wellness.     

A generic morphological model of the anatomic variability in the m. flexor digitorum profundus, m. flexor pollicis longus and mm. lumbricales complex

This study examined the productivity and representation of past-tense marking in children with and without specific language impairment (SLI). Participants were 11 6-year-olds with SLI, 11 age-matched controls, and 11 MLU-matched controls. Regular and irregular verbs were used to examine the productivity of regular marking. Past-tense representation was examined by asking children to inflect homophonous pairs of denominal and irregular root verbs. All three groups demonstrated productive marking of past tense, although as expected the accuracy of the impaired groups was less than that of earlier control group. Patterns of past-tense marking as a function of a word's phonological composition and inflectional frequency were the same for the SLI- and MLU-matched groups, and all children presented a past-tense system that was sensitive to grammatical structure. The findings replicate previous research of the SLI morphological system and provide additional specification of these children's morphological strengths and weaknesses. Strengths include the children's sensitivity to grammatical and phonological characteristics of the lexicon; weaknesses include limited productivity of regular past-tense marking and a greater sensitivity to frequency manipulations as compared to normally developing children. Results are discussed in terms of the nature of the SLI profile. They also are used to evaluate the theoretical model on which the study was based.