Human CD4+ T cells displaying viral epitopes elicit a functional virus-specific memory CD8+ T cell response

The Ag-specific cellular recall response to herpes virus infections is characterized by a swift recruitment of virus-specific memory T cells. Rapid activation is achieved through formation of the immunological synapse and supramolecular clustering of signal molecules at the site of contact. During the formation of the immunological synapse, epitope-loaded MHC molecules are transferred via trogocytosis from APCs to T cells, enabling the latter to function as Ag-presenting T cells (T-APCs). The contribution of viral epitope expressing T-APCs in the regulation of the herpes virus-specific CD8+ T cell memory response remains unclear. Comparison of CD4+ T-APCs with professional APCs such as Ag-presenting CD40L-activated B cells (CD40B-APCs) demonstrated reduced levels of costimulatory ligands. Despite the observed differences, CD4+ T-APCs are as potent as CD40B-APCs in stimulating herpes virus-specific CD8+ T cells resulting in a greater than 35-fold expansion of CD8+ T cells specific for dominant and subdominant viral epitopes. Virus-specific CD8+ T cells generated by CD4+ T-APCs or CD40B-APCs showed both comparable effector function such as specific lysis of targets and cytokine production and also did not differ in their phenotype after expansion. These results indicate that viral epitope presentation by Ag-specific CD4+ T cells may contribute to the rapid recruitment of virus-specific memory CD8+ T cells during a viral recall response.

Heart rate and energetics of free-ranging king penguins (Aptenodytes patagonicus)

The main objective of this study was to determine heart rate (fh) and the energetic costs of specific behaviours of king penguins while ashore and while foraging at sea during their breeding period. In particular, an estimate was made of the energetic cost of diving in order to determine the proportion of dives that may exceed the calculated aerobic dive limit (cADL; estimated usable O2 stores/estimated rate of oxygen consumption during diving). An implanted data logger enabled fh and diving behaviour to be monitored from 10 free-ranging king penguins during their breeding period. Using previously determined calibration equations, it was possible to estimate rate of oxygen consumption (VO2) when the birds were ashore and during various phases of their foraging trips. Diving behaviour showed a clear diurnal pattern, with a mixture of deep (>40 m), long (>3 min) and shallow (<40 m), short (<3 min) dives from dawn to dusk and shallow, short dives at night. Heart rate during dive bouts and dive cycles (dive + post-dive interval) was 42% greater than that when the birds were ashore. During diving, fh was similar to the 'ashore' value (87+/-4 beats min(-1)), but it did decline to 76% of the value recorded from king penguins resting in water. During the first hour after a diving bout, fh was significantly higher than the average value during diving (101+/-4 beats min(-1)) and for the remainder of the dive bout. Rates of oxygen consumption estimated from these (and other) values of fh indicate that when at sea, metabolic rate (MR) was 83% greater than that when the birds were ashore [3.15 W kg(-1) (-0.71, +0.93), where the values in parentheses are the computed standard errors of the estimate], while during diving bouts and dive cycles, it was 73% greater than the 'ashore' value. Although estimated MR during the total period between dive bouts was not significantly different from that during dive bouts [5.44 W kg(-1) (-0.30, +0.32)], MR during the first hour following a dive bout was 52% greater than that during a diving bout. It is suggested that this large increase following diving (foraging) activity is, at least in part, the result of rewarming the body, which occurs at the end of a diving bout. From the measured behaviour and estimated values of VO2, it was evident that approximately 35% of the dives were in excess of the cADL. Even if VO2 during diving was assumed to be the same as when the birds were resting on water, approximately 20% of dives would exceed the cADL. As VO2 during diving is, in fact, that estimated for a complete dive cycle, it is quite feasible that VO2 during diving itself is less than that measured for birds resting in water. It is suggested that the regional hypothermia that has been recorded in this species during diving bouts may be at least a contributing factor to such hypometabolism.

Improvement of glucose metabolism in patients with type II diabetes after treatment with a hemodialysate

Insulin resistance of skeletal muscle glucose uptake is a prominent feature of Type II diabetes (NIDDM); therefore, pharmacological intervention should aim to improve insulin sensitivity. Previous studies have shown that Actovegin, a hemodialysate of calf blood, which has been used for treatment of circulatory disorders for many years, improves glucose tolerance in NIDDM without affecting insulin levels; in vitro studies found an improvement of insulin-stimulated glucose uptake in adipocytes. This pilot study was initiated to see whether this compound augments insulin sensitivity after repeated treatment. Ten patients with NIDDM received the hemodialysate (Actovegin 2.000 pro infusions, 500 ml as daily infusions) over a period of 10 days. A hyperinsulinaemic, isoglycaemic glucose-clamp was done on day 0 and day 11; oral glucose tolerance test (oGTT) was done on day -4 and day 12. Parenteral administration of the hemodialysate markedly augmented insulin stimulated glucose disposal (glucose infusion rate and metabolic clearance rate) by more than 80% (p < 0.003 day 11 vs. day 0). Although tested 44 h after the last infusion, oGTT also improved significantly, as documented by the diminished area under the curve (AUC) for glucose, whereas the AUC for insulin remained unchanged. This is the first clinical study to show that parenteral administration of the tested hemodialysate results in a significant increase of insulin-stimulated glucose disposal in NIDDM. The exact mode of action of the hemodialysate in improving insulin sensitivity is currently not known. The hemodialysate possibly acts via a supplementation of inositol-phosphate-oligosaccharides (IPO), as in experimental studies IPOs isolated from the hemodialysate improved glucose uptake in adipocytes in an insulin-independent manner. Further studies are needed to elucidate the underlying mechanisms.

Confirmed clinical efficacy of Actovegin in elderly patients with organic brain syndrome

A double-blind randomized clinical trial was performed comparing the therapeutic effects of Actovegin versus placebo in elderly patients with organic brain syndrome. In addition to the necessary basic internal medicine therapy, 40 geriatric patients received dialy intravenous infusions of 250 ml Actovegin 20% p.i., and 20 patients received 250 ml 0.9% saline solution as placebo over a period of four weeks. Of the patient sample, 58% were hospitalized for simple dementia (ICD-9: 290.0) and 42% due to senile dementia with depressive or paranoid symptoms (ICD-9: 290.2). Based on the Syndrome Short Test (SKT) and the Sandoz Clinical Assessment Geriatric Scale (SCAG) score, the patients suffered from mild to moderate dementia. The therapeutic effect on the total SCAG score and the Clinical Global Impression (CGI) were the primary study variables. The scores for the SCAG subscales and the SKT score served as secondary variables. The mean total SCAG score in the drug group decreased from 56.3 at the start of therapy to 36.3 points at the end of therapy, and in the placebo group the total score went from 61.2 to 52.0 (p < 0.01). The CGI showed that with Actovegin, 70% of the patients experienced "distinct improvement" or "improvement" compared to only 35% with such results in the placebo group. The SCAG subscales and the total SKT score also demonstrated the superior effects of Actovegin compared to placebo. Moreover, the therapy group treated with Actovegin showed greater improvements in social behavior and mental performance than did the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Fibrin-glue-coated collagen fleece in lung surgery--experimental comparison with infrared coagulation and clinical experience

Diffuse parenchymal bleeding and major air leaks still present a challenge to the thoracic surgeon. This study was therefore designed to evaluate efficacy and handling of fibrin-glue-coated collagen fleece, to address these problems. In an experimental part defects were produced in lungs of troll pigs to compare the use of the fleece with infrared coagulation. Immediate airtightness and postoperative adhesions were evaluated. Scores were designed to evaluate quality and extension of the adhesions. In a clinical study parenchymal resection sites were sealed with fibrin-glue-coated collagen fleece in 52 patients. No patient suffered from postoperative bleeding. In three cases air leaks were still present on the third postoperative day, representing a 5.8% failure rate. 92.3% of the patients showed neither postoperative hemorrhage nor prolonged air leaks. A fixed combination of collagen fleece and fibrin glue consequently can be considered as a valuable tool in thoracic surgery.

Influence of deproteinized hemodialysate on rest pain and walking distance in the presence of peripheral chronic arterial occlusive disease

In a controlled and randomized single-blind study (blind observer) the clinical efficacy of intra-arterial therapy with a metabolically active deproteinized dialysate from calf blood has been tested against a vasodilating and hemorheologically active reference substance (bencyclan). Over a period of four weeks 28 patients each received 20 intra-arterial infusions of the deproteinized hemodialysate 20% for infusion. The reference group with 30 patients was treated with 250 mg bencyclan in 250 mL saline 0.9%. As for the target criteria, rest pain and consumption of analgesics, the hemodialysate treatment proved superior to the therapy with the reference substance. Both preparations induced to a small extent pain-free walking distances: hemodialysate group, 29.2 +/- 14.6 m; reference group, 25.8 +/- 18.7 m (group difference not significant).

Haemostyptic preparations on the basis of collagen alone and as fixed combination with fibrin glue

Preparations containing collagen play a prominent role among local haemostyptic agents in surgery. Sheets of collagen are used as degradable haemostyptic tampons. Various investigations have shown better haemostasis with collagen compared to other degradable materials, although the haemostyptic effect of these collagen preparations is limited. Concerning the mechanism of haemostasis, not all the reactions stimulated, e.g. by the collagen of an injured vessel wall, may be activated by a haemostyptic tampon from collagen. This depends very much on the kind of preparation. The combined application of a sheet of collagen with fibrin glue improved local haemostasis to a great extent. Large areas of capillary bleeding can be treated successfully with this method. Despite the very good results, this method has not been applied on a broad scale. This is due to the necessary skill and experience and the relatively cumbersome preparation required at the operation site. These drawbacks have been overcome with the latest development in this field--a sheet of collagen covered with a fixed layer of the solid components of a fibrin glue (fibrinogen, thrombin and aprotinin). The performance of this new local haemostyptic agent is described with special emphasis on the results of clinical trials. Haemostasis of large areas of capillary bleeding was very efficient and safe with the new material. Moreover, bile leakage and liquor, pancreatic and aerial fistulae could be sealed without problems.

Malignant intracerebral granular cell tumor reacts positively with anti-alpha-1-antichymotrypsin and the MB2 antibody: a clue to the histogenesis of the brain granular cell?

A 50-year-old man developed a granular cell tumor (GCT) of the right hemisphere (parieto-occipital) with visual deterioration and headache. Two months after surgery the tumor relapsed with diffuse infiltration of the right hemisphere, the corpus callosum and the adjacent left hemisphere. Subsequently, radiotherapy (5000 rads) was applied. Controls two and four months after the radiotherapy did not show any signs of the tumor in the computerized tomogram (CT). Light- and electronmicroscopy showed typical type I (small) and type II (large) granular cells with irregularly rounded or oval nuclei, abundant cytoplasm and PAS positive granules. Immunohistochemistry was positive with anti-alpha-1-antichymotrypsin (ACT) and the MB2 antibody. A survey of the relevant literature is given with special emphasis on the impact of the results of immunohistochemistry on the histogenesis of the CNS granular cell. Finally, some aspects of the therapy of GCTs will be discussed.

Whose structure is it anyway?

While "structure" is a term that is widely used in psychiatric nursing practice, few nurse authors have clearly defined the concept. This article offers an operational definition of structure, and proposes a theoretical basis to the client's need for structure. A case presentation, as well as characteristics of an effective structure, are also described.

The conformer nature of the multiple forms of beef liver catalase as obtained by biochemical and small-angle X-ray scattering experiments. A model for the quaternary structure of the beef liver catalase molecule

Two of the five multiple forms of beef liver catalase have been extensively studied using biochemical and biophysical analysis techniques. The two molecules, cat I and cat V, have different isoelectric points (pH 6.55 and 5.6), different surface charges (25.8 and 32.7 elementary charges) and display different numbers of primary amino groups on their surfaces. The numbers of tyrosine residues on the surfaces of the two molecules are also different (16 and 10 at pH 10). Since the two forms of catalase can be interconverted, the described changes may be caused by conformational changes of the four protein subunits within the molecule. This mobility of the polypeptide chains is also demonstrated by the different absorption spectra below 390 nm. Using small-angle X-ray scattering, the radii and the volumes of the two catalase forms were shown to be different (cat 1 is smaller than cat V). All five multiple forms of beef liver catalase are concormers of the molecule. A model for the quaternary sturcture of the beef liver catalase are conformers of the molecule. A model for the quaternary structure of the beef liver catalase molecule is suggested. It consists of a regular configuration of four prolate rotational ellipsoids (semiaxes: a = 52 A, b = c = 21 A) in close contact in which the nearest neighbour subunits are shifted by 37 A parallel to each other. Thus the height of the complete molecule is 141 A and the diameter 94 A.