Molecular cloning and physical characterization of integrated equine infectious anemia virus: molecular and immunologic evidence of its close relationship to ovine and caprine lentiviruses

Molecular clones of the integrated form of the genome of equine infectious anemia virus (EIAV), the etiologic agent of a naturally occurring, worldwide disease of horses, were obtained. The restriction map of a full-length genome was determined. Additional evidence for the close evolutionary relationship between EIAV and a prototype lentivirus (caprine arthritis encephalitis virus) was acquired by Southern blotting and immunological analyses. An interspecies radioimmunoassay was developed in which EIAV and ovine and caprine lentiviruses could be detected equally well. These studies make available precisely defined reagents to pursue the study of the mechanisms of pathogenesis of lentiviral induced diseases.     

Mechanism of activation of an N-ras oncogene of SW-1271 human lung carcinoma cells.

An N-ras-related transforming gene was detected in the human lung carcinoma cell line SW-1271 and molecularly cloned. The lesion responsible for its acquisition of transforming activity was localized to a single nucleotide transition from A to G in codon 61 of the predicted protein. This lesion in the second exon results in the substitution of arginine for glutamine at this position. These findings, together with previous studies, indicate that the activation of ras oncogenes in human tumors is most commonly due to point mutations at one of two major "hot spots" in the ras coding sequence.     

Type II antithrombin deficiency caused by a large in‐frame insertion: structural,functional and pathological relevance

Summary. Background: The metastable native conformation of serpins is required for their protease inhibition mechanism, but also renders them vulnerable to missense mutations that promote protein misfolding with pathological consequences. Objective: To characterize the first antithrombin deficiency caused by a large in‐frame insertion. Patients/Methods: Functional, biochemical and molecular analysis of the proband and relatives was performed. Recombinant antithrombin was expressed in HEK‐EBNA cells. Plasma and recombinant antithrombins were purified and sequenced by Edman degradation. The stability was evaluated by calorimetry. Reactive centre loop (RCL) exposure was determined by thrombin cleavage. Mutant antithrombin was crystallized as a dimer with latent plasma antithrombin. Results: The patient, with a spontaneous pulmonary embolism, belongs to a family with significant thrombotic history. We identified a complex heterozygous in‐frame insertion of 24 bp in SERPINC1, affecting strand 3 of β‐sheet A, a region highly conserved in serpins. Surprisingly, the insertion resulted in a type II antithrombin deficiency with heparin binding defect. The mutant antithrombin, with a molecular weight of 59 kDa, had a proteolytic cleavage at W49 but maintained the N‐terminal disulphide bonds, and was conformationally sensitive. The variant was non‐inhibitory. Analysis of the crystal structure of the hyperstable recombinant protein showed that the inserted sequence annealed into β‐sheet A as the fourth strand, and maintained a native RCL. Conclusions: This is the first case of a large in frame‐insertion that allows correct folding, glycosylation, and secretion of a serpin, resulting in a conformationally sensitive non‐inhibitory variant, which acquires a hyperstable conformation with a native RCL.     

Acute surgical unit safely reduces unnecessary after-hours cholecystectomy

Introduction

The acute surgical model has been trialled in several institutions with mixed results. The aim of this study was to determine whether the acute surgical model provides better outcomes for patients with acute biliary presentation, compared with the traditional emergency surgery model of care.

Methods

A retrospective review was carried out of patients who were admitted for management of acute biliary presentation, before and after the establishment of an acute surgical unit (ASU). Outcomes measured were time to operation, operating time, after-hours operation (6pm – 8am), length of stay and surgical complications.

Results

A total of 342 patients presented with acute biliary symptoms and were managed operatively. The median time to operation was significantly reduced in the ASU group (32.4 vs 25.4 hours, p=0.047), as were the proportion of operations performed after hours (19.5% vs 2.5%, p<0.001) and the median length of stay (4 vs 3 days, p<0.001). The median operating time, rate of conversion to open cholecystectomy and wound infection rates remained similar.

Conclusions

Implementation of an ASU can lead to objective differences in outcomes for patients who present with acute cholecystitis. In our study, the ASU significantly reduced time to operation, the number of operations performed after hours and length of stay.     

Relational psychophysiology: Lessons from mother–infant physiology research on dyadically expanded states of consciousness

Abstract

The authors illustrate how their work on mother–infant “relational psychophysiology” might inform psychotherapy research. They examined psychophysiology in 18 mother–infant dyads (infants' age: 5 months) during normal interaction and a still-face perturbation. They measured respiratory sinus arrhythmia (RSA) as an index of emotion regulation and explored whether skin conductance (SC) concordance, previously linked to therapist empathy, occurs in mothers and infants. During the still-face episode, SC concordance correlated to infant negative engagement. Upon reengagement, when mothers often soothe their infants, concordance instead correlated to behavioral synchrony, an index of maternal sensitivity. Furthermore, maternal RSA became correlated to infant negative engagement. These findings suggest that a mother trying to calm her infant calms herself physiologically and her sensitivity on a behavioral level becomes coherent physiologically. Implications for psychotherapy research are discussed.     

Subsyndromal depressive symptoms and major depression in postpartum women

This study documents differences in the psychosocial functioning of women three months postpartum with subclinical depression, major depression prior to the birth of the baby, major depression both pre- and post-birth, and no depression. An understanding of these differences may have implications for intervention insofar as maternal depression places at risk not only the mother's functioning but her infant's development, as well.     

Role of presynaptic purinoceptors and cyclic AMP on the noradrenaline release in cat cerebral arteries

Field electrical stimulation (ES), K+ (50 mM) or ionophore X-537A (0.01 mM) induced tritium release from cat cerebral arteries preincubated with [3H]noradrenaline (NA). Adenosine and AMP (0.5 mM) did not modify tritium release caused by ionophore X-537A, but these agents and ATP (0.5 mM) significantly reduced that elicited by ES and K+; this reduction was antagonized by 1-methyl-3-isobutylxanthine (MIX; 0.05 mM). Inosine (0.5 mM) and the agonist of purinergic A2-receptors, 5'N-ethyl-carboxamide adenosine (NECA; 0.5 mM) had no effect, but the agonist of purinergic A2-receptors L-N6-phenylisopropyl adenosine (L-PIA; 0.1 mM) diminished tritium efflux caused by ES and K+. The adenosine inhibition of ES-induced radioactivity release was not affected by indomethacin (0.05 mM). MIX (0.05 mM) increased tritium release evoked by ES and K+. Agents that increase intracellular cyclic (c)AMP levels, such as dibutyryl cAMP (0.5 mM), the phosphodiesterase inhibitor Ro 20-1724 (0.1 mM), and the activators of adenylate cyclase, forskolin (0.005 mM) and NaF (2 mM) reduced tritium secretion elicited by ES and K+. However, the intracellular increase of cyclic GMP (cGMP) caused by 8-Br-cGMP did not affect this secretion. Dipyridamole (0.05 mM) and the adenosine deaminase inhibitor erythro-9-2-hydroxy-3 nonyl adenosine (EHNA; 0.1 mM) also produced inhibition of tritium secretion elicited by ES and K+. Dipyridamole reduced both the uptake of [3H]NA and [3H]adenosine.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparative double-blind study of terbinafine (Lamisil) and griseofulvin in tinea corporis and tinea cruris

In a double-blind randomized study, 92 patients with culturally proven tinea corporis and/or tinea cruris were treated orally with either terbinafine (Lamisil) (125 mg b.i.d.) or griseofulvin (500 mg b.i.d.) for up to 6 weeks. The two groups of patients and distribution of the target lesions were similar, but the analysis of the clinical scores showed that the terbinafine group had slightly higher mean scores at baseline (P = 0.186). At the end of therapy the proportion of patients with negative microscopy and culture was 78% in the terbinafine group and 83% in the griseofulvin-treated group. At the assessment 8 weeks after the end of therapy the percentages of terbinafine- and griseofulvin-treated patients with negative mycology were 93 and 95%, respectively. There were three relapses after mycological cure in the griseofulvin group (8%) and two in the terbinafine group (4%). Griseofulvin-treated patients were treated for shorter periods than terbinafine-treated patients (i.e. 58% compared to 26% received only 2-4 weeks of therapy). In terms of overall effectiveness, there were no significant differences between the two treatments. Thirty-seven terbinafine patients (77%) compared to 36 griseofulvin patients (82%) had overall effective therapy. Eight terbinafine patients (16%) compared to 10 griseofulvin patients (20%) experienced at least one adverse event. Five patients in the terbinafine group and six in the griseofulvin group had to stop the treatment due to headaches or gastrointestinal disorders. One terbinafine patient had an elevation of liver function tests after 6 weeks of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)