Analysis of 3H-histamine interaction with lymphocytes: receptor binding or uptake?

The immunoregulatory role of histamine is presumably mediated by specific receptors on the plasma membrane of lymphocytes. However, using murine spleen cells and a whole cell assay commonly applied in hormone receptor studies, specific histamine receptors with an affinity higher than that of non-specific binding could not be identified. Nevertheless, approximately 30% of the totally bound histamine was undissociable over a range of added histamine concentrations (9 X 10(-6)-1 X 10(-2) M). Lectin stimulation of spleen cells caused an additional two-fold increase of undissociable histamine. The H1 receptor antagonist, diphenhydramine, blocked histamine uptake, whereas the H2 receptor antagonist, cimetidine, had no effect. Binding experiments carried out at 4 degrees C demonstrated that the amount of undissociable histamine was much reduced. Even at 4 degrees C, evidence for specific membrane associated histamine receptor could not be obtained. It was therefore concluded that lymphocytes take up histamine by an energy-dependent mechanism inhibitable by diphenhydramine but not cimetidine, and that the usual hormone receptor methodology did not allow the identification of specific membrane associated histamine receptors.

Enhanced production of hepatitis B surface antigen in NIH 3T3 mouse fibroblasts by using extrachromosomally replicating bovine papillomavirus vector

We have constructed a recombinant pBR322 plasmid composed of a subgenomic transforming fragment of bovine papillomavirus DNA and the hepatitis B surface antigen gene from cloned hepatitis B virus DNA and used it for transfection of NIH 3T3 mouse fibroblasts. The transformed cells retain the plasmids in extrachromosomal form with a copy number of about 50 to 100 per cell. Expression of the hepatitis B surface antigen gene linked to bovine papillomavirus DNA is independent of its orientation relative to the bovine papillomavirus vector. Cell lines continuously secreting high amounts of hepatitis B surface antigen into the medium could be established. The antigen is released into the culture medium as 22-nm particles, having the same physical properties and constituent polypeptides as those found in the serum of hepatitis B virus-infected patients.

Total synthesis of yeast alanine transfer ribonucleic acid

By a combination of chemical and enzymatic methods, small oligonucleotides with lengths varying from 2 to 8 nucleotides were synthesized from mononucleotides. The small oligonucleotides were then ligated with T4 RNA ligase into six large oligonucleotides (9 to 19 nucleotides long) which were further ligated to form two half molecules with 35 and 41 nucleotides respectively. Finally, the two synthetic half molecules were annealed and ligated to obtain the whole molecule of yeast alanine tRNA (tRNAAlay). Prior to this, two semi-syntheses were performed, i.e. ligation of the synthetic 5'-half molecule with the natural 3'-half molecule and that of the natural 5'-half molecule with the synthetic 3'-half molecule. Both the semi-synthetic tRNAAlay and the synthetic tRNAAlay occupy the same position as the natural tRNAAlay after electrophoresis on a 20% polyacrylamide gel. They have the same chemical composition (containing 9 modified nucleotides of 7 different species) and structure as the natural tRNAAlay and are biologically active, i.e. accepting and transferring alanine into proteins in a cell-free protein synthesizing system, the accepting activity of the synthetic product is 52-66% of that of the natural tRNAAlay and 91-106% of that of the reconstituted product of the two natural half molecules. The incorporation activity of alanine into proteins of the synthetic 3H-alanine tRNAAlay is 63%, corresponding to 91% of that of the natural tRNAAlay and 115% of that of the reconstituted product of the two natural half molecules. To the best of our knowledge, this is the first time that a natural RNA with biological activity is synthesized.

Acute upper gastrointestinal bleeding in the aged. A retrospective analysis of 100 cases

One hundred consecutive patients (predominantly men, aged 60 years and older), who were admitted to the Hsinhua Hospital, Shanghai, with acute bleeding from the gastrointestinal tract during a three-year period, were reviewed. The most common causes of bleeding were peptic ulcers, chronic gastritis, prolapse of gastric mucosa, and other benign conditions. In 22 patients, bleeding was either due to oesophageal varices, or was a complication of cor pulmonale. The incidence of malignant disease was 23% (higher than that reported from the United States or the United Kingdom). The mortality rate in patients with benign causes of gastrointestinal bleeding (after exclusion of patients with malignant disease, cor pulmonale, and hepatic cirrhosis) was 4.4%--much lower than the British rate, but slightly higher than that reported in an Australian study. It is hoped that, with the increasing interest in geriatrics, and closer attention to acute bleeding from the gastrointestinal tract in the aged, the mortality rate from this condition will decline.

Effects of villin on the polymerization and subunit exchange of actin

We have investigated the Ca2+ -dependent interactions of villin, a protein of the intestinal microvillar core, with actin by monitoring resonance energy transfer between fluorescently labeled actin subunits. In the presence of elevated free Ca2+ (approximately 20 microM), villin affects both the nucleation and the elongation phases of actin polymerization. Consistent with previous reports, villin stimulates the nucleation process and will form stable nuclei under depolymerization conditions. Compared to the control, the net rate of polymerization is slightly inhibited at low concentrations of villin (villin/actin approximately 1:400) but is stimulated at higher concentrations (villin/actin greater than 1:100). Villin also significantly increases the critical concentration of actin polymerization. Addition of either villin or villin-actin complexes induces depolymerization of preassembled actin filaments. This villin-induced depolymerization is reversible upon removal of free Ca2+ or upon the addition of phalloidin. The exchange of actin subunits at steady state is inhibited at low concentrations of villin (villin/actin approximately 1:200) but is stimulated at higher concentrations (villin/actin approximately 1:50). None of the above effects is observed at less than 10(-8) M free [Ca2+].

Aging and immunity: decrease in interleukin-2 production and interleukin-2-dependent RNA-synthesis in lectin-stimulated and murine spleen cells

The RNA-content of G1 cells in lectin-stimulated spleen cell cultures of young and aged NMRI mice was determined by flow cytometry. In spleen cells of aged mice a preferential decrease of G1 cells with a high RNA-content, so-called G1b cells, was found. Since, as shown in a previous report, only cells with a high RNA-content are able to proliferate and the passage of low (G1a) to high (G1b) RNA-content is interleukin-2(IL-2)-dependent, the ability of young and old spleen cells to produce IL-2 was tested. In old spleen cells a diminished production of IL-2 was found. Addition of external IL-2, however, did not increase the proliferative capacity of old spleen cells, nor did it induce more G1b cells. Thus spleens of aged mice contain cells, which can be activated by lectin, but then fail to respond to IL-2. Both decrease in IL-2 production and receptivity for IL-2 may contribute to the diminishing immune response in aging individuals.

Expression of hepatitis B surface antigen in unselected cell culture transfected with recircularized HBV DNA

Hepatitis B virus (HBV) DNA was isolated from the recombinant plasmid pA01 -HBV and recircularized . Immediately after introduction of this DNA into mouse fibroblasts (NIH 3T3) we observed increasing release of hepatitis B surface antigen (HBsAg) into the culture medium. Later production of HBsAg declined to a lower but constant level. No dominant selective marker and foreign promoter were necessary in this system, which therefore can be used for the study of regulation of HBsAg expression.

Rest and exercise hemodynamics after the Fontan procedure

Sixteen consecutive patients (12 with tricuspid atresia) underwent a Fontan procedure, with no operative deaths. There were three late deaths. Eleven of the survivors were electively catheterized 4-25 months postoperatively. Rest and exercise hemodynamics were measured in five patients, and resting hemodynamics alone were measured in three. All exercised patients were New York Heart Association class I Cardiac index was low at rest (2.3 +/- 0.61/min/m2) and during exercise (4.9 +/- 1.11/min/m2) due to a low stroke index both at rest (28 ml) and exercise (35 ml). Accordingly, mixed venous oxygen saturations were decreased (66% at rest and 31% during exercise). These values are significantly lower than those at rest and during exercise from 23 control patients of similar age and size. Heart rates, pulmonary vascular resistances, and left ventricular filling pressures appeared normal both at rest and during exercise. High right atrial pressure at rest (15 mm Hg) was associated with minimal conduit gradient (2 mm Hg). However, exercise increased the mean conduit gradient to 8 mm Hg, demonstrating significant functional conduit obstruction. As expected, the cardiovascular response to exercise is abnormal after the Fontan procedure, even in asymptomatic patients. This abnormal response may be exacerbated by conduit obstruction, and conduit obstruction may not be apparent during resting studies.

Liposomes as gene carriers: efficient transformation of mouse L cells by thymidine kinase gene

Stable transformation of mouse L cells deficient in thymidine kinase was achieved by liposome-mediated transfer of a recombinant plasmid carrying the thymidine kinase gene. Ten percent of the recipient cells expressed thymidine kinase activity. The transformed phenotype (for example, 200 out of 10(6) cells) was stable under selective and nonselective conditions. The liposome technique is compared with other methods currently used for gene transfer.

Gene transfer into mouse lyoma cells by electroporation in high electric fields

Electric impulses (8 kV/cm, 5 microseconds) were found to increase greatly the uptake of DNA into cells. When linear or circular plasmid DNA containing the herpes simplex thymidine kinase (TK) gene is added to a suspension of mouse L cells deficient in the TK gene and the cells are then exposed to electric fields, stable transformants are formed that survive in the HAT selection medium. At 20 degrees C after the application of three successive electric impulses followed by 10 min to allow DNA entry there result 95 (+/- 3) transformants per 10(6) cells and per 1.2 micrograms DNA. Compared with biochemical techniques, the electric field method of gene transfer is very simple, easily applicable, and very efficient. Because the mechanism of DNA transport through cell membranes is not known, a simple physical model for the enhanced DNA penetration into cells in high electric fields is proposed. According to this ' electroporation model' the interaction of the external electric field with the lipid dipoles of a pore configuration induces and stabilizes the permeation sites and thus enhances cross membrane transport.

Recombinant retroviral DNA yielding high expression of hepatitis B surface antigen

A genomic fragment of hepatitis B virus encoding the surface antigen (HBsAg) was inserted into the proviral genome of Moloney mouse sarcoma virus (MSV), obtained from the mouse cell line G8 -124. The recombinant DNA was introduced into NIH 3T3 mouse fibroblasts. Cells, morphologically transformed by the oncogene of MSV (v-mosM) were selected, established as cell lines and tested for expression of HBsAg. An expression level of up to 4.5 micrograms/10(7) cells/day was detected.

The pathophysiology of angina pectoris and the effect of lidoflazine

Angina pectoris results from a deficiency in myocardial oxygen supply. The rate-pressure product is an important predictor of myocardial oxygen requirements in patients with ischemic heart disease and in normal persons. The rate-pressure product at the onset of angina pectoris is reproducible under a variety of circumstances with a suitable protocol. In some patients, coronary artery spasm may reduce myocardial blood flow and contribute to the development of angina pectoris. Lidoflazine is a synthetic drug that appears to be a calcium-entry blocker and results in symptomatic improvement in patients with angina pectoris. Lidoflazine reduces the exercising rate-pressure product by its effect on heart rate and by decreasing systemic vascular resistance. It decreases coronary vascular resistance and antagonizes processes leading to an increase in coronary vasomotor tone.

Randomized trial of standard therapy with or without poly I:C in patients with superficial bladder cancer

Thirty-two patients with superficial urinary bladder tumors were stratified for four variables and randomized after complete transurethral resection and/or fulguration of tumor to receive standard therapy with or without intravenous Poly I:C. Cystoscopies were performed at three- to four-month intervals for up to 48 months. While there was no statistically significant difference in the tumor recurrence rates in the two groups during the first year, a significant increase (P = 0.003) in survival at four years was observed between the Poly I:C group and the control group. The difficulties in evaluating the efficacy of anti-neoplastic agents in the treatment of superficial bladder tumors are discussed.

Clinical and hemodynamic results with the St. Jude Medical cardiac valve prosthesis. A three-year experience

Two hundred thirty-two consecutive patients (October 3, 1977, through December, 31, 1980) underwent aortic (AVR), mitral (MVR), or double (DVR) valve replacement with the St. Jude Medical (SJM) prosthesis. Operative mortality for the entire group was 7.3%. There was 100% follow-up. Warfarin (Coumadin) anticoagulation was recommended for all patients. There were no cases of mechanical failure. The incidence of thromboembolism was 0.6/1,000 patient-months for those with AVR, 3/1,000 patient-months for those with MVR, and 0% for those with DVR. Thrombosis of a prosthesis occurred in two patients with DVR. Clinically significant hemolysis occurred in three patients with paravalvar leaks following MVR. Late postoperative prosthetic infection has not occurred. Postoperative catheterization studies in 33 patients revealed no transvalvular gradient at rest in 21 patients. The remainder of the patients catheterizd had low transvalvular gradients. There was a minimal increase in transvalvular gradient with exercise. The SJM cardiac valve is a viable alternative in the surgical therapy of valvular heart disease.

Prostatic cancer. I. 6-Methylene-4-pregnen-3-ones as irreversible inhibitors of rat prostatic delta 4-3 ketosteroid 5 alpha-reductase

Some derivatives of 6-methylene-4-pregnen-3-one were studied as inhibitors of delta 4-3-ketosteroid 5 alpha-reductase. Maximum inhibitory activity was shown by 17-acetoxy-6-methylene-4-pregnene-3,20-dione (AMPD). Irreversible inactivation was observed following preincubation of the enzyme with NADPH and AMPD. This inactivation was found to occur only in the presence of NADPH. As such enzyme inactivation was not due to the formation of a more inhibitory metabolic product, or to the formation of superoxide via a cytochrome P-450/NADPH pathway, it seemed likely that the observed inactivation was derived from an irreversible combination of the enzyme with AMPD. That this was probably the case was established by kinetic studies which revealed a pattern compatible with a kcat type of mechanism.

Electrocardiogram made on ascending the Mount Qomolangma from 50 m a. s. l

In May 1975, one female mountaineer and eight male mountaineers of our country once more climbed onto the highest peak of the world Mount Qomolangma from the north slope. At the same time, we recorded 15 electrocardiograms while they were climbing from 7,600 m to the peak(8,848.13m) through radio-operated electrocardiography. In this report we mainly analyze the characteristics of electrocardiogram of six mountaineers who ascended the peak at the stage from 50 m a. s. l. to over 8,200m a. s. l. The result proves that although obvious changes after reaching an altitude above 8,200 m from the plain region should be those of indexes of heart rates, the QRS axis, Q-TR, Q-T/T-Q, P wave and T wave, there is no T wave diphasic, inverted, flat or abnormal shifting of S-T segment in the electrocardiogram of these outstanding mountaineers. This fully proves that those summit climbers are of excellent constitution and good adaptation ability to hypoxia. This also shows that the people who have been trained and acclimatized under hypoxia conditions (including permanent altitude residents and native lowlanders) can maintain normal physiological functions under ultra-anoxia for quite a long time.

The effect of lithium carbonate on leukopenia after chemotherapy

To evaluate the efficacy of lithium carbonate in ameliorating leukopenia, 37 patients (3 to 26 years old, mea (less than or equal to 1,000/mm3) over 40% of the time were designated at random on the last day of 82 separate chemotherapy courses to receive lithium or no treatment. Four could not take the drug because of the size of the capsules. There were 39 controls and 39 patients given lithium. Blood levels were maintained at 0.2 to 1.2 mEq/1 (median 0.7). The median drop of WBC in the treated group was 3,400/mm3 with a nadir of 1,800/mm3 vs 5,000 and 1,400, respectively, for the untreated patients (P LESS THAN 0.01). Eight patients (21%) in the lithium-treated group became severly leukopenic (less than or equal to 1,000/mm3) while 14 (36%) in the control group became leukopenic to that extent. Twenty-four patient days were spent with the WBC less than or equal to 1,000/mm3 after lithium and 57 days in the control group. Three patients required admission for 24 hospital days for fever while leukopenic after lithium, whereas seven patients spent 62 days in the hospital in the control group. Lithium reduces the period of leukopenia after chemotherapy during which time the patients may acquire infections.

Circulating immune complexes, complement and complement component levels in childhood Hodgkin's disease

Serum levels of circulating immune complexes (CIC) assayed by the Raji cell radioimmunoassay, total haemolytic complement (TCH50), Clq and C3 were correlated with clinical stage, histological type, age, sex and treatment of eighty-six children with Hodgkin's disease over a period of 4 years. Most significant findings were the changes of levels of CIC, TCH50, Clq and C3 during disease activity and following treatment. Significant perturbations were also seen in association with relapse. Levels of C and CIC were significantly elevated (P less than 0.001) at the time of diagnosis prior to splenectomy and/or any treatment. In the group before treatment, 81 percent of CIC levels were above 16 micrograms/ml with a maximum value of 1120 micrograms/ml. During treatment 33 percent were still above normal with a maximum of 320 micrograms/ml. Within 1 year after cessation of treatment, 37 percent also remained above normal levels with a maximum of 240 micrograms/ml. At relapse prior to treatment, 63 percent were again elevated with a maximum of 1280 micrograms/ml. The most significant difference on TCH50 levels relates to treatment periods. Sera of patients with active disease who are previously untreated show elevation of TCH50 levels (P less than 0.001) (average 127 CH50 mu/ml. During and after treatment eht TCH50 levels drop to 96 and 102 CH50 mu/ml, as compared to normal control of 100 CH50 mu/ml. In sera of patients at the first, second or third relapse, the combined TCH50 levels are significantly different from controls and across treatment periods (P less than 0.005).

A new method of treatment of congenital tibial pseudoarthrosis using free vascularised fibular graft: a preliminary report

This paper reports our experience of using Vascularised Fibular Transfer in Treatment of Congenital Pseudoarthrosis of tibia in 12 cases. Although the preliminary results of bony union are encouraging, the long term results can only be assessed after skeletal maturity.

Circulating immune complexes in sera of children with neuroblastoma: correlation with stage of disease

The presence of circulating immune complexes (ICS) in freshly drawn sera of 67 children with neuroblastoma was studied by the Raji cell radioimmunoassay of Theofilopoulos et al. (J. Clin. Invest. 57: 169--182), with particular emphasis on the correlation of levels of ICS with stage of disease and changes attributable to treatment. There was a close correlation between amount of complexes and stage of disease and treatment. Levels of ICS increased as the stage of the disease advanced, and were significantly higher (P less than 0.005) in stage IV than in all other stages combined. When patients with stage IV disease were subdivided into "before," "during," and "after" treatment groups, there was a significant decrease in ICS levels as treatment progressed. Studies of complement and complement components did not give such a clear relationship. A significant decrease of hemolytic C1 values was found in patients with "active disease" compared to normal age-matched controls. Some high C3 levels, determined immunochemically, were associated with low hemolytic levels of C3, which were attributed to C3 cleavage detected by immunoelectrophoresis. Based on our survival data, ICS, which were significantly different in 20 patients now decreased when compared to those of other patients, are very valuable in the prognosis of neuroblastoma.

Composite replacement of the aortic valve and ascending aorta

This report comprises 16 consecutive patients with ascending aortic aneurysms caused by cystic medical necrosis. We replaced the ascending aorta and aortic valve with a tightly woven Dacron graft containing a Lillehei-Kaster valve prosthesis and implanted the coronary ostia in the sides of the graft. All but two patients had massive aortic insufficiency. Postoperative catheterization was performed in 13 patients, and all surviving patients have been seen within the past 6 months. There was one perioperative death (6 percent) and two late deaths. Eleven survivors are in Class I and two are in Class II (N.Y.H.A.). Angiographically demonstrated late complications have included psuedoaneurysms of the coronary ostium (two), paravalvular leak (one), and pseudoaneurysm of the distal suture line (one). Two of these four patients were asymptomatic. Two of the four patients have had successful repair of these defects and a third is awaiting operation. Compositive replacement carries a low operative risk and minimizes problems of intraoperative bleeding. In view of the incidence of late suture line problems, routine angiography 6 to 12 months postoperatively is recommended. If new symptoms occur or if there is a change in the cardiac silhousette on chest roentgenogram, the patient should be recatheterized.

Hemodynamic evaluation of Lillehei-Kaiser and Starr-Edwards prosthesis

The central-flow low profile disc-valve prosthesis has been offered as an alternative to ball- and tissue-valve prostheses. Extensive laboratory investigation with both pulse duplicator and experimental animals has been reported for the Lillehei-Kaster prosthesis. A series of patients receiving this prosthesis underwent postoperative cardiac catheterization to better define the hemodynamic function of this prosthesis in vivo. Because of the variations in reports of hemodynamic data from various institutions, the results of post-operative studies in an earlier group of patients with Starr-Edwards prostheses were used as a standard for comparison. Good hemodynamic function was found with the pivoting-disc prosthesis in all but the smallest valve sizes. Lillehei-Kaster and early model Starr-Edwards prostheses with equivalent tissue annulus dimensions were found to have nearly equal valve areas in vivo in the aortic position. The Lillehei-Kaster mitral valves provided larger areas than Starr-Edwards prostheses in large tissue annulus sizes.