On the number and nature of antigen-sensitive lymphocytes in the blood of delayed-hypersensitive human donors.

The virus plaque assay has been successfully employed to enumerate antigen-sensitive cells in the peripheral blood lymphocyte populations of tuberculin-hypersensitive human donors. The method is based on the finding that, while resting lymphocytes are unable to produce a variety of viruses upon infection, lymphocytes activated by specific antigens become capable of virus replication. The average number of antigen-sensitive cells detected in cell populations from donors reacting to first test strength or intermediate test strength tuberculin was approximately 3.6/1000 lymphocytes, and the averages for both groups were similar. Studies on the kinetics of appearance of these virus plaque-forming cells and on the effects of the mitotic inhibitor, vinblastine, indicate that the activation of these antigen-sensitive cells is a linear process and that the cells must be nondividing cells during this process. These qualities contrast markedly with those described for the mitogenic response and the antibody-producing cells which require cell division and increase exponentially. On the basis of these experiments it is suggested that the antigen-sensitive cell measured in the virus plaque assay is the effector cell in delayed-type hypersensitivity reactions and, in addition, may be one of the cells critically involved in antibody formation.

Using metabolomics to dissect host-parasite interactions.

Protozoan parasites have evolved diverse growth and metabolic strategies for surviving and proliferating within different extracellular and intracellular niches in their mammalian hosts. Metabolomic approaches, including high coverage metabolite profiling and (13)C/(2)H-stable isotope labeling, are increasingly being used to identify parasite metabolic pathways that are important for survival and replication in vivo. These approaches are highlighting new links between parasite carbon metabolism and the ability of different parasite stages to colonize specific niches or host cell types. They have also revealed novel metabolic regulatory mechanisms that are important for homeostasis and survival in potentially nutrient variable environments. These studies highlight the importance of parasite and host metabolism as determinants of host-parasite interactions.

Characterization of the simian adenovirus type 30 inverted terminal repeat.

The presence of an inverted terminal repeat (ITR), which plays an important role in the initiation of DNA replication, is one of the characteristic properties of adenoviruses (Ads). We have established the nucleotide (nt) sequences for the ITR of simian adenovirus type 30 (SV30), a subgroup-III oncogenic virus. This repeat consists of 185 nt, representing the longest ITR found in an Ad so far. It contains multiple copies of internal repeats, as well as the consensus sequences of the putative binding sites for replication and transcription factors. The conserved features of the known ITRs are also found in SV30. Interestingly, the ITR of SV30 is more closely related to that of Ad5 (human), than to that of SA7 (simian).

Isolation of a human cDNA of urokinase and its expression in COS-1 cells.

The cDNA encoding human urokinase (UK) has been isolated from a cDNA library prepared from human normal fibroblast (WI38) cells, which had been stimulated by endothelial cell growth factor and heparin. This cDNA was sequenced and found to contain a few silent substitutions, thus encoding the same amino acids as deduced from the published genomic sequence of UK. After modification, the cDNA of UK was inserted into a transient expression vector and used to transfect COS-1 cells. The recombinant UK protein (rUK) in the serum-free medium of transfected COS-1 cells was characterized by biochemical and functional assays. These studies indicated that rUK from COS-1 cells is glycosylated, enzymatically active, and very similar to native single-chain plasminogen activator (scuPA). Therefore, such rUK can be a convenient source of scuPA for any further studies.

Construction and characterization of adenovirus co-expressing hepatitis B virus surface antigen and interleukin-6.

Coexpression of biologically active interleukin 6 (IL-6), an immunoregulator, and hepatitis B virus surface antigen (HBsAg), an immunogen, was obtained using an adenovirus type 7 (Ad7) vector. Two recombinant adenoviruses (re-Ad) containing both the HBsAg and IL6 genes were constructed: one virus was capable of expressing IL6 with its signal peptide (spIL6) (Ad7::spIL6::HBsAg), and the second virus lacked this sequence (Ad7::IL6::HBsAg). A third recombinant contained only HBsAg (Ad7::HBsAg). All three Ad constructs were plaque purified and characterized in the A549 human lung cell line. The growth kinetics of the recombinants were similar to wild-type (wt) Ad7. The production and secretion of HBsAg (p24 and gp27) from cells infected with each re-Ad were at a level greater than 9 micrograms/10(6) cells by 118 h postinfection. Two IL-6 of approx. 24 and 27 kDa were produced and secreted into the culture medium from cells infected with Ad7::spIL6::HBsAg, and maximal accumulation occurred by 92 h p.i. at a level > 260 ng/10(6) cells. One cell-associated IL-6 of approx. 23 kDa was produced from cells infected with Ad7::IL6::HBsAg at a level > 12 ng/10(6) cells. Importantly, the Ad-produced IL-6 were determined to be biologically active by enhancing immunoglobulin production in lymphoblastoid cells. The co-production of IL-6 with HBsAg did not affect growth of these recombinant Ad, immunoreactivity of HBsAg, or the biological activity of IL-6 in tissue culture cells.

Heparin potentiates endothelial cell growth factor stimulation of plasminogen activator synthesis by diploid human lung fibroblasts.

Endothelial cell growth factor (ECGF) stimulates the synthesis of t-PA and u-PA by confluent, diploid human lung fibroblasts, and this activity is potentiated considerably by heparin. In contrast, the malignant cell lines, Bowes melonoma and CALU-3, producers of t-PA and u-PA, respectively, are insensitive to ECGF. Studies with metabolic inhibitors and direct measurements of PA-specific mRNAs show that ECGF-mediated production of PA by human lung fibroblasts is dependent on de novo protein and RNA synthesis. The mechanism by which heparin potentiates this effect is thought to reside in its ability to prolong or strengthen the interaction of ECGF with cell surface receptors. The results raise the possibility that endogenous ECGF or related polypeptides (and heparin) may act to regulate PA synthesis by lung fibroblasts and possibly other responsive target cells in vivo.

Comparison of dipyridamole-echocardiography with dipyridamole-thallium scintigraphy for the diagnosis of myocardial ischemia.

After an intravenous infusion of dipyridamole (0.56 mg/kg), we performed both echocardiography and thallium scintigraphy in 63 patients who were referred for known or suspected coronary artery disease. Of those patients, 25 returned for coronary arteriography within 1 month after the tests, thus forming the study group for this report. Sensitivity for detection of coronary artery disease, when analyzed region-by-region, was 80% for thallium scintigraphy and 57% for echocardiography, whereas specificity was 85% and 98%, respectively. When evaluating individual patients for the presence or absence of ischemia, we found a sensitivity of 95% for scintigraphy and 58% for echocardiography; corresponding specificities were 50% and 100%. By using arteriography as the gold standard for comparison, it appears that thallium scintigraphy has a significantly higher sensitivity but lower specificity for the detection of coronary artery disease than does echocardiography. Echocardiography may, however, be a useful adjunct to thallium scintigraphy in the evaluation of patients with coronary artery disease.

[Suicidal gunshots through the mouth in patients with dental prostheses]. / Suizidale Mundschüsse bei Trägern von Zahnprothesen.

An analysis of the forensic autopsies performed in Freiburg showed that 21% of the suicides by shooting involved a shot into the mouth. Persons in their 7th and 8th decade of life accounted for 11% of the suicides by shooting. In this age the percentage of denture-wearers is particularly high. Accordingly gunshot-related damages of complete or partial dentures are likely to be seen in forensic practice. These may involve both the denture base (mostly consisting of polymethyl methacrylate) and the teeth (made of synthetic or ceramic material). At autopsies the following findings could be seen; entry defect in the palatal part of the maxillary prosthesis larger than the calibre, funnel-shaped widening (bevelling) of the gunshot hole on the palatal side, fracture lines in the denture base radiating from the gunshot hole, injuries in the palatal soft tissues due to denture fragments, fractures of the front teeth region of the prosthesis due to the recoil impact of the foresight as well as soot soiling of the denture base and the lingual surfaces of the front teeth. The findings observed in autopsies could be experimentally reproduced by test shots on isolated complete maxillary prostheses.

[Animal experiment studies of hemostasis using the fibrinogen adhesive system on the liver and spleen in coagulation disorders]. / Tierexperimentelle Untersuchungen zur Blutstillung mittels des Fibrinogenklebesystems an Leber und Milz bei Gerinnungsstörungen.

Fresh resection areas after partial resection of liver and lien in rabbits were repaired and sealed by a fibrin film on conditions of hemorrhagic tendency and increased fibrinolysis. A strong damage in the wound area in the same way as in organic injury originates from these pathologic conditions. A premature demarcation of the external wound strata especially in raised fibrinolysis takes place by reason of the parenchymal necrosis though the fibrinogen is cross-linked to an intact film independent of the common circulation and clotting relations. An abundant wound revision is recommended before using the fibrin adhesive to prevent an after-bleeding.

[Effect of discontinuous hemorrhage on plasma and cerebrospinal fluid vasopressin concentration in anesthesized rabbits]. / Einfluss der diskontinuierlichen Hämorrhagie bei narkotisierten Kaninchen auf die Vasopressinkonzentration in Plasma und Liquor cerebrospinalis.

Repeated withdrawal of 15 ml arterial blood at 10 min intervals produced marked hypovolaemia and hypotension with plasma vasopressin concentration increasing exponentially from 53 microE/ml to more than 700 microE/ml contrary to the hypovolaemia. After the first blood withdrawal there exists a linear correlation between the increase of the plasma vasopressin concentration and the decrease of the mean arterial blood pressure. With 61.5 microE/ml the cerebrospinal fluid withdrawn following the last bleeding likewise showed a very high vasopressin level. After extraction of the hormone from plasma and cerebrospinal fluid the vasopressin concentration was determined by means of the antidiuretic bioassay in the water-loaded rat.

[Heart position as a determinant of the voltage of the R wave in healthy subjects]. / La posición cardíaca como determinante del voltaje de la onda R en sujetos sanos.

Although many factors have been reported to change the R wave amplitude of the electrocardiogram, the direct measurement without any consideration, has been the method of choice, which leads to controversial findings. We hypothesized that body mass index and heart position are the main modifiers of the R wave amplitude. To test this hypothesis 80 normal subjects were studied with standard electrocardiograms in which correlation with constitutional variables were performed and were also analyzed according to the electrocardiographic heart position. R wave amplitude showed a non-significant inverse relationship to body mass except in severe overweight subjects (p less than 0.05). When analyzed by position, levorotated and S1, S2, S3 hearts showed a significant increase in R wave voltage whereas horizontal and dextrorotated ones showed a diminished amplitude (p less than 0.01) independent of body weight. There was no relation between R wave voltage and body surface. We conclude that: Body mass is not an important modifier of R wave amplitude in thin, normal and light overweight subjects. Heart position may induce significant variation of R wave voltage according to the degree of the projection of the left ventricular electric field to the anterior thoracic surface.

[The auxiliary transplantation of a portion of liver in an animal experiment]. / Die auxiliäre Transplantation eines Leberteiles im Tierexperiment.

The authors inform about a model for auxiliary liver part transplantation in pig. Intra-abdominal narrowness which can lead to failure of the transplant can avoided by this model. In the transplant was carried out an extensive left resection with purse-string ligature of all visible vessels and cystic ducts. The resection surface is sealed by a tissue adhesive. An auxiliary transplanted part of the liver can also operate on a heterotopic location of the organism.

Pulmonary hyalinizing granulomas in a patient with malignant lymphoma, with development nine years later of multiple myeloma and systemic amyloidosis.

In our patient, multiple bilateral nodular pulmonary densities appeared on a chest x-ray at the time of diagnosis of stage IV diffuse lymphocytic lymphoma. After localized radiation therapy, the patient received no further systemic therapy. The pulmonary nodules slowly became larger and more numerous. Nine years later the patient developed proven multiple myeloma. Pulmonary hyalinizing granulomas have not heretofore been associated with proven lymphoreticular neoplasia, although this has long been suspected. The occurrence of two B-cell tumors at different points in time associated with systemic amyloidosis is an extremely rare event. The authors discuss the possibility that these conditions represent an abnormality in a common cell of origin with differing expression over time. Coincidence, however, remains a likely explanation for the different immunopathies that occurred in our patient.

The simian immunodeficiency virus (SIV) rev gene regulates env expression.

The rev gene product is a trans-acting nuclear regulatory protein that is essential for AIDS virus replication. To define the effect of the SIV rev gene on its gp160 expression, two SV40 constructs have been made: pBC17 is a rev+env+ construct, and pBD21 is a rev-env+ construct. After transfecting the constructs into COS-1 cells, RNA, protein, syncytium formation, and monoclonal antibody blocking assays were performed. The results indicated that the SIV rev gene positively influenced the level of full-length env mRNA and was required for expression of SIV gp160.