Screening for Depression in the Medically Ill: a comparison of self-report measures, clinician judgment, and DSM-IV diagnoses

The performance of the self-report 10-item Depression in the Medically Ill scale was observed in 210 patients as part of clinical assessment by consultation-liaison psychiatry clinicians. Both the Depression in the Medically Ill scale and the Beck Depression Inventory for Primary Care were completed by the patient, and the clinicians made their judgment of the presence and severity of "clinical depression" and DSM-IV affective disorder diagnoses. Both the Depression in the Medically Ill scale and the Beck Depression Inventory for Primary Care detected 85% of patients with DSM-IV major depressive episode. The Depression in the Medically Ill scale was slightly superior to the Beck Depression Inventory for Primary Care in its relationship to clinicians' judgments of clinical depression caseness.     

An in vivo role for Trypanosoma cruzi calreticulin in antiangiogenesis

Angiogenesis leads to neovascularization from existing blood vessels. It is associated with tumor growth and metastasis and is regulated by pro- and antiangiogenic molecules, some of them currently under clinical trials for cancer treatment. During the last few years we have cloned, sequenced and expressed a Trypanosoma cruzi calreticulin gene (TcCRT). Its product, TcCRT, a 45 kDa protein, is more than 50% identical to human CRT (HuCRT). TcCRT, present on the surface of trypomastigotes, binds both C1q and mannan binding lectin and inhibits the classical activation pathway of human complement. Since TcCRT is highly homologous to a functional antiangiogenic fragment from HuCRT (aa 120–180), recombinant (r) and native (n) TcCRT were tested in their antiangiogenic effects, in the chick embryonic chorioallantoid membrane (CAM) assay. Both proteins mediated highly significant antiangiogenic effects in the in vivo CAM assay. This effect was further substantiated in experiments showing that the plasmid construct pSecTag/TcCRT also displayed significant antiangiogenic properties, as compared to the empty vector. Most likely, the fact that antiangiogenic substances act preferentially on growing neoplasic tissues, but not on already established tumors, is due to their effects on emerging blood vessels. The results shown here indicate that TcCRT, like its human counterpart, has antiangiogenic properties. These properties may explain, at least partly, the reported antineoplasic effect of experimental T. cruzi infection.     

Immunogenicity of polymeric implants: long-term antibody response against polyester (Dacron) following the implantation of vascular prostheses into LEW.1A rats

Implanted biomaterials trigger acute and chronic inflammatory responses directly correlated to the central role of phagocytic cells at the host-implant interface. This study was designed to evaluate specific humoral immune responses following repeated intraperitoneal implantations of collagen-impregnated polyester (Dacron) prosthetic segments into LEWIS rats. Serum antibody detection was performed by enzyme immunoassay with the prosthetic segments as a target. Cutoff values for antibody positivity were greater than or equal to the 99th percentile for control rats. Polymer immunoglobiulin G (IgG) antibodies were significantly increased (p < 0.05) by repeated implantation and were subsequently followed until experimental day 293. Antibody formation was significantly enhanced through the application of complete Freund's adjuvant in combination with the first implantation. All rats within this group were antibody-positive on day 53, but only 6 of 10 animals that received the prosthesis without the adjuvant were. After preincubation of sera with bovine collagen type I (solid phase adsorbed or in solution), polymer antibody binding was discovered not to be diminished, indicating that the IgG antibodies detected were not directed against the prosthesis impregnation. Furthermore, a significant correlation was obtained between polymer antibody binding to collagen-impregnated and nonimpregnated prostheses (r(s) = 0.797, p < 0.001). There was no substantiated correlation between antibody binding to polyester and to an irrelevant polymer (Tecoflex EG 80). We conclude that specific polymer antibodies may indeed provide an additional parameter for biocompatibility testing as well as a possible serological marker of an inflammatory response to implants.     

Deoxyuridylate-hydroxymethylase of bacteriophage SPO1.

Phage SPO1 of Bacillus subtilis carries hydroxymethyl-deoxyuridylate in place of thymidylate in its DNA. The enzyme, responsible for the conversion of dUMP to HmdUMP, is a dUMP hydroxymethylase, encoded by the SPO1 gene 29. Here we describe the cloning and sequencing of the gene and the overexpression of the gene product. DNA hybridization using the DNA of bacteriophage T4 dCMP-hydroxymethylase gene as a probe, allowed us to identify and map g29 on a 3.9-kb restriction fragment, EcoRI*11. We determined the nucleotide sequence. One of the open reading frames detected, coding for a putative 44.6-kDa protein, showed significant amino acid homologies with all known thymidylate synthases. Gp29 was overexpressed in the pT7 system. Extracts prepared from induced cells show hydroxymethylase activity in a tritium release assay.     

Swelling,Elasticity and Spatial Inhomogeneity of Poly(N,N‐dimethylacrylamide) Hydrogels Formed at Various Polymer Concentrations

Summary: The equilibrium swelling degree, modulus of elasticity and the spatial inhomogeneity of poly(N,N‐dimethylacrylamide) (PDMAAm) hydrogels were investigated over the entire range of the initial monomer concentration. The degree of dilution of the networks after their preparation was denoted by ν, the volume fraction of crosslinked polymer after the gel preparation. The linear swelling ratio of the gels increased linearly with increasing ν. Depending on the value of ν, three different gel regimes were observed: (1) For ν < 0.3, increasing ν decreases the extent of cyclization during crosslinking so that the effective crosslink density of gels increases with rising ν. (2) For 0.3 < ν < 0.7, increasing ν reduces the accessibility of the pendant vinyl groups during crosslinking due to steric hindrance at high polymer concentrations. As a result, the effective crosslink density of gels decreases with increasing ν. (3) For ν > 0.7, the modulus of elasticity increases sharply with increasing ν due to the increasing extent of chain entanglements in this high concentration regime. Static light scattering measurements on the gels show that the degree of spatial gel inhomogeneity in PDMAAm gels attains a maximum value at ν = 0.06. The appearance of a maximum as well as the ν‐dependence of scattered light intensities from gels was successfully reproduced by the theory proposed by Panyukov and Rabin.

Effective crosslink density ν_e of the hydrogels shown as a function of ν.     

Relationship between slow-wave EEG bursts and heart rate changes in preterm infants

The objective of the study is to explore interactions between cortical and autonomic functions in the first weeks of postnatal life. We investigated the behaviour of one-channel electroencephalogram (EEG) patterns and heart rate (HR) dynamics in preterm infants. In a group of 15 healthy preterm infants with a mean conceptional age (CA) of 36 weeks and a mean postnatal age of 17.5 days simultaneous registration of amplitude integrated EEG (aEEG) and HR pattern was performed during interfeeding intervals. Periods with a discontinuous EEG activity and a low heart-rate variability (HRV) were selected for further processing and averaging. It was found that spontaneous activity transients (SATs) or slow wave EEG bursts during "Tracé alternant" (TA) can be accompanied by an HR acceleration of 1-2% (mean: 1.9, range: 0.6-3.5 beats/min) lasting approximately 5s (mean, range: 3.6-7.1s). The aim of the study is to give evidence of a coherent behaviour of EEG bursts and HR in the developing nervous system of preterm infants.