Nucleotide sequence of a promoter recognized by Bacillus subtilis RNA polymerase

We report the nucleotide sequence of a promoter recognized by RNA polymerase from the gram-positive bacterium Bacillus subtilis. This promoter, which was isolated from B. subtilis phage SP01 DNA, is homologous to promoters for Escherichia coli RNA polymerase; the sequences of the "-35 region" and the "Pribnow box" were 5'TTGACT and 5'CATAAT, respectively (T is the thymine analog 5-hydroxymethyluracil in SP01 DNA). These sequences each differed by only a single base pair from the preferred sequences for E. coli promoters. Not surprisingly, the SP01 promoter was actively transcribed in vitro by E. coli RNA Polymerase as well as by B. subtilis RNA polymerase.

Effects of oral pentaerythritol tetranitrate in cardiac failure and angina pectoris. Assessment by hemodynamic measurement and exercise capacity

Oral pentaerythritol tetranitrate produces sustained beneficial hemodynamic effects in patients with cardiac failure of varied etiology. The principle action is a reduction of elevated left ventricular filling pressure. In a small group of angina patients, the oral nitrate in high dosage resulted in considerable increase in angina-limited exercise capacity compared to placebo for four hours following drug administration. No side effects were associated with ingestion of pentaerythritol tetranitrate in these investigations.

Possible relationship between glycosphingolipids and the formation of metastasis in certain human experimental tumors

Two tumors, human sarcoma #1 (HS #1) and human epidermoid carcinoma #3 (HEp #3), were cultured on the chorioallantoic membrane of chick embryos. Under experimental conditions, HS #1 does not metastasize, whereas HEp #3 metastasizes extensively to chick embryo lungs and other organs. The glycosphingolipid profiles of these tumors were studied and HEp #3 wad found to contain about 2.5-fold less lipid-bound sialic acid per 100 mg of total lipid extracted than did HS #1, due mainly to smaller levels of monosialoganglioside (3.7-fold) and disialoganglioside (3.8-fold) in HEp #3. The total amount of neutral glycosphingolipids was approximately the same in both tumors, but their profiles differed. Treatment of these tumors with 6,7,8,9-tetrahydro-1-mercapto-1,2,4-triazolo-[4,3-a]quinazolin-5-ol (2.5 mg/egg/tumor) completely inhibited the formation of metastases in HEp #3 and increased the total content of lipid-bound sialic acid in the tumor by 63% (hematoside, monosialoganglioside, and disialoganglioside by 71, 99, and 67%, respectively). No change was seen in the content of lipid-bound sialic acid in HS #1. Treatment of HEp #3 with a smaller dose of te quinazolinol derivative (1.25 mg/egg) caused an average of 88% inhibition of metastasis, with a 37% increase in lipid-bound sialic acid. Another compound, 2,5-diphenylthiazolo-[5,4-d]thiazole (500 microgram/egg), completely inhibited the formation of metastasis and caused a substantial increase in the amount of lipid-bound sialic acid (77%). The data showed the existence of a correlation between the level of gangliosides in HEp #3 and the ability of these tumors to metastasize.

Nurse practitioners in a jailhouse clinic

Six primary nurse practitioners were introduced into a large urban jail health service along with supportive organizational changes. The system's primary care volume capacity doubled. The average cost of each patient visit decreased by about one third. The technical quality of primary care improved continuously during a 3-year period of study while patient outcomes, patient satisfaction levels and overall mortality rates remained unchanged. The inmate suicide rate decreased after the introduction of a psychiatrically directed screening and treatment program, and cardiopulmonary resuscitation (CPR) training for correctional officers. Attribution of the decrease awaits further experience. The nurse practitioners delivered primary care equal in technical quality of care provided by medical subspecialty Fellows. A test of clinical knowledge proved to be a good predictor of the technical quality of care delivered by individual graduate nurse practitioners. One measure of the quality of management of illness episodes in the jail clinic correlated weakly with two measures of patient outcome. The addition of nurse practitioners into a well-organized, well-monitored jail health program was a cost-effective means of expanding the program's patient volume capacity. Screening and referral of inmates with high suicide potential, coupled with CPR training for correctional officers, may have been a factor in reducing the inmate suicide rate.

Induction of resistant hepatocytes as a new principle for a possible short-term in vivo test for carcinogens

The induction of resistant hepatocytes in vivo in the rat has been observed with 21 different chemical carcinogens. The resistance was measured by the ability of the cells to proliferate as focal lesions in the presence of an environment that inhibits the original or surrounding hepatocytes from proliferation. This was created by a dietary 2-acetylaminofluorene plus a stimulus for cell proliferation, a single necrogenic dose of CCl4. The foci were readily visualized by staining for gamma-glutamyl transpeptidase activity. With most of the chemicals, a single administration at an appropriate time after partial hepatectomy is efficacious. However, with safrole and dieldrin, three doses over a 36-hr period were required to induce a significant number of foci of resistant hepatocytes. The presumptive preneoplastic nature of the resistant hepatocytes and the possible usefulness of this approach for the development of a new in vivo short-term test system for carcinogens are discussed.

Evaluation of transluminal angioplasty of chronic coronary artery stenosis. Value and limitations assessed in fresh human cadaver hearts

The possibility of increasing reduced blood flow in atherosclerotic coronary obstruction by catheter balloon dilatation offers a nonsurgical approach to relieve clinical coronary stenosis. To assess the ability of effectively dilating such diseased vessels by transluminal angioplasty, we used the Grüntzig balloon-tipped catheter in 12 fresh human cadaver hearts in which the intervention was performed in 21 noncalcified stenotic areas, including each of the three major coronary arteries. Quantitative coronary arteriography documented decreased obstruction of each lesion; luminal diameter increased 58% (1.9 +/- 0.2 mm to 2.8 +/- 0.3; p less than 0.001) and luminal diameter relative to the most proximal normal coronary segment diminished 61% (46 +/- 4% to 18 +/- 3%; p less than 0.001). Angioplasty was most successfully applied in proximal, discrete, noncalcified lesions of the right and left anterior descending coronaries; calcified, tortuous, middle and distal lesions and the left circumflex coronary were entered with difficulty or unapproachable. Histologic examination revealed microanatomic changes, most often endothelial disruption and atheroma compression, but no serious vascular tears. Dilatation beyond normal coronary diameter caused vessel rupture. This study extends elucidation of the value and limitations of percutaneous transluminal angioplasty in the clinical use of this technique in selected patients for relieving coronary obstruction without surgery.

Dansylated thyrotropin as a probe of hormone-receptor interactions

A strongly fluorescent 5-dimethylamino-1-naphthalene sulfonate (dansyl) derivative of bovine thyrotropin has been prepared. The dye-conjugated hormone is bioactive and shares, essentially unchanged, the membrane binding and adenylate cyclase stimulatory activities of the native hormone. Binding of 125I-labeled dansyl-thyrotropin to thyroid plasma membranes is sensitive to inhibition by gangliosides and, as is the case for the binding of 125I-thyrotropin, galactosyl-N-acetylgalactosaminyl[N-acetylneuraminyl-N-acetylneuraminyl]-galactosylglucosylceramide (GDIb) is the most potent binding inhibitor. Gangliosides interact with dansyl-thyrotropin, causing a large increase of the quantum yield and a 5- to 10-nm blue shift of the emission maximum of the hormone-bound naphthalene chromophore; gangliosides cause no change in the fluorescent properties of the free dye. The fluorescence enhancement caused by gangliosides can be specifically reversed by unlabeled thyrotropin. The effect of gangliosides on dansyl-thyrotropin fluorescence is strongly salt-dependent; salts cannot, however, reverse the formation of the dansyl-thyrotropin.ganglioside complex once it has formed. The salt data suggest that the association of the ganglioside with dansyl-thyrotropin is dominated by electrostatic interactions, but that salt-independent, short range interactions, most likely hydrophobic, dominate the dissociation of the dansyl-thyrotropin-ganglioside adduct. Sucrose gradient centrifugation, ultracentrifugation, and fluorescence polarization data indicate that the gangliosides are micellar in nature under the conditions of these experiments. Acid titration of dansyl-thyrotropin causes a marked quenching of dansyl fluorescence which in part reflects dissociation of the hormone into its constituent alpha and beta subunits. In the presence of GDIb, but not N-acetylneuraminylgalactosyl-N-acetylgalactosaminyl-[N-acetylneuraminyl]-galactosylglucosylceramide (GDIa), pH-dependent quenching and subunit dissociation are essentially eliminated. Circular dichroism results and fluorescence polarization studies support the interpretation that the ganglioside interaction causes a conformational change in the thyrotropin molecule. The acid titration data together with differences in the ability of gangliosides to influence the tyrosine fluorescence of the thyrotropin molecule indicate that different gangliosides induce different conformational perturbations in the thyrotropin molecule.

Role of phospholipids in the structure and function of the thyrotropin receptor

Phosphatidylinositol, phosphatidylserine, and phosphatidylethanolamine interact with 125I-thyrotropin and inhibit its binding to thyroid plasma membranes; phosphatidylcholine is not similarly effective. The interaction has been monitored by column chromatography on Sephadex G-100 which shows, for example, that 125I-labeled thyrotropin forms an adduct with phosphatidylinositol but not with phosphatidylcholine. Formation of the 125I-labeled thyrotropin-phosphatidylinositol adduct is dependent on the phosphatidylinositol concentration but can be reversed by both unlabeled thyrotropin and excess membranes. The efficacy of the phospholipid interaction and the phospholipid inhibition of thyrotropin binding to thyroid membranes is paralleled by changes in fluorescence and fluorescence polarization imposed on the 5-dimethylamino-1-naphthalene sulfonate (dansyl) derivative of thyrotropin. These changes are reversed by unlabeled thyrotropin but not by prolactin, placental lactogen, or growth hormone; similar changes are not observed when phospholipids are incubated with dansylated growth hormone, prolactin, and placental lactogen. Monovalent potassium, sodium, and lithium salts neither prevent nor reverse the formation of the phospholipid-dansyl-thyrotropin adduct; these results contrast with the effects of the same salts on the formation of ganglioside adducts with dansyl-thyrotropin. Despite their ability to interact witw 125I-thyrotropin in solution, neither phosphatidylinositol, phosphatidylserine, nor phosphatidylethanolamine, when incorporated in a liposome, binds the 125I-labeled ligand. These same phospholipids have no effect on ganglioside binding of 125I-labeled thyrotropin when gangliosides are incorporated in a liposome. These phospholipids do, however, modulate the expression of the glycoprotein component of the thyrotropin receptor when it is imbedded in a liposome. The phosphatidylinositol in this case serves as a negative modulator, both by decreasing the incorporation of the glycoprotein component of the receptor into the liposome and by inhibiting the binding activity of the glycoprotein component which is incorporated. Speculation is offered as to a possible role of the phospholipids in the message transmission process which would be consistent with current studies demonstrating a direct interaction of acidic phospholipids with thyrotropin. The effect of phospholipids on liposomes containing the glycoprotein component of the thyrotropin receptor raises the possibility that phospholipids and, in particular, phosphatidylinositol, may also play a role in regulating the insertion and expression of this receptor component in thyroid plasma membranes.

The fate of fetal and adult B-cell progenitors grafted into immunodeficient CBA/N mice

The relative ability of various precursors to generate functional B cells in vivo was assessed by transferring normal, chromosomally-marked CBA/H-T6T6 cells to irradiated or unirradiated immunodeficient CBA/N mice. Emergence of donor-derived B cells was monitored by means of a B-cell cloning assay (in which CBA/N cells are inactive), and by karyotpic analysis of lymphoid, myeloid, and stem cell metaphases. Grafts of lymph node, spleen, anti-mu surface immunoglobin suppressed bone marrow, sIg+ cell-depleted marrow, normal marrow, fetal liver, and yolk sac suggest: (a) there is little self-renewal of sIg+ B cells in these models; (b) pre-committed cells have extensive proliferative/differentiative potential and at least initially contribute most of the newly-formed B cells; (c) populations or pre-B cells obtained from various sources differ in their regenerative ability; (d) CBA/N mice are deficient in a category of pre-B cells which are found in fetal liver; and (e) selective B-cell chimerism results from grafting of unirradiated CBA/N mice.

Abnormalities in clonable B lymphocytes and myeloid progenitors in autoimmune NZB mice

Cloning procedures were used to study B lymphocytes and progenitors of granulocytes and macrophages in NZB mice. Numbers of B cells that were detected in sheep erythrocyte-containing semisolid cultures were only slightly elevated in NZB tissues, and these were normally sensitive to inhibition by anti-mu or anti-delta antibodies or prostaglandin E. However, NZB mice rapidly developed large numbers of B cells that could be cloned in the presence of lipopolysaccharide, and these included unusual anti-mu resistant cells. Numbers of myeloid precursors in NZB bone marrow that were responsive to colony-stimulating activity in L-cell conditioned medium or endotoxin serum were at least normal, but at all ages granulocyte-macrophage precursors were poor responders in cultures stimulated by WEHI-3 cell conditioned medium. Almost no colonies were elicited in NZB cultures with a colony-stimulating activity moiety from WEHI-3 cells. Prostaglandin sensitivity of myeloid precursors from NZB and CBA mice was also different. Codominant genetic control of these abnormalities was suggested by their partial expression in F1 hybrid NZB X CBA and NZB X NZW mice. NZB mice expressed an unexpected IgD allotype allele.

Critical micelle concentrations of gangliosides

The micellar properties of mixed, bovine gangliosides and purified galactosyl-N-acetylacetylgalactosaminyl (N-acetylneuraminyl) galactosylglucosylceramide were studied by gel filtration, equilibrium dialysis, and band and boundary centrifugation in sucrose gradients. The dissociation of micelles is very slow (days) in water and required us to approach equilibrium by association of monomers rather than by the dissociation of micelles. The gangliosides were therefore first converted into very low molecular weight aggregates (1-3 molecules) by dissolving them in Me2SO. Galactosyl-N-acetylgalactosaminyl(N-acetylneuraminyl)galactosylglucosylceramide was then diluted into aqueous sucrose gradients and sedimented by the boundary centrifugation technique. This gave a sedimenting micelle and a nonsedimenting monomer concentration of (1-2) x 10-10 M (or less) which corresponds to the critical micelle concentration value. The mixed gangliosides revealed two micellar sizes (i.e., 10 and 4.5 S), the slower sedimenting species being formed from the larger one with time (days). The critical micelle concentration of the mixed gangliosides was found to be approximately 10-8 M by a gel filtration, equilibrium dialysis, and band centrifugation.

Relationships of the structure and function of the interferon receptor to hormone receptors and establishment of the antiviral state

This report describes similarities between the structure and function of the interferon receptor and receptors for glycoprotein hormones and several bacterial toxins. Specifically, it describes several common molecular and mechanistic elements, including: (a) the presence of a glycoprotein as well as a ganglioside component in the receptor; (b) changes in membrane structure as a consequence of interferon action; (c) interferon-induced intracellular cyclic adenosine 3':5'-monophosphate changes; and (d) alterations in the flux of certain ions across the membrane. Since interferon has an antiviral effect, these results define a relationship between hormonal perturbation of cellular events and the ability of an agent to prevent or suppress viral infections of cells. Further definition of these relationships should be important to our understanding of the oncogenic state, of hormonal effects on the oncogenic state, and of other human diseases in which hormonal perturbations of non-target tissues or cross-reactivity of receptors could be pathogenic.

A correlative microscopical analysis of differentiating ovarian follicles of mammals

The mammalian ovary has been studied by optical microscopy and by scanning and transmission electron microscopy with the purpose of presenting an integrated view of the differentiating mammalian follicle. During follicular development, changes in the granulosa cells are particularly noteworthy and include dramatic modifications in cell shape coincident with antrum formation. The cytoplasmic processes of those granulosa cells immediately surrounding the oocyte, as well as the more peripheral granulosa cells comprising a second and third layer, traverse the zona pellucida, infrequently interdigitate with the microvilli of the egg, and make both desmosomal and gap junction contacts with the oocyte. The zona pellucida is thus distinguished by numerous fenestrations of varying diameters. The membrana limitans (basal lamina) is a bipartite structure composed of (a) a homogenous stratum upon which the peripheral layer of granulosa cells rests, and (b) an outer region of collagen-like fibers. The specific advantages and limitations of the different methodologies utilized to study folliculo-genesis are discussed.

Structural basis for the changing physical properties of human pulmonary vessels with age

Circumferential strips of pulmonary vessel wall were obtained at necropsy from the major arterial and venous branches at the lung hilum in patients aged 7-87 years. The extensibility of these strips was measured using the tension balance method of Harris et al. (British Heart Journal, 1965, 27, 651-659). The vessels were then bisected, and half of each strip was submitted for structural analysis using morphometric methods on paraffin sections stained to show the collagen, elastin, and muscle content. The other halves of the formalin-fixed vessel strips were examined chemically to determine their collagen content by estimation of the total hydroxyproline content. The thickness of the vessel media was measured microscopically on all of the sections examined. Quantitative measurements were made on 42 arteries and 37 veins. Contrary to expectation, there was a steady fall in medial collagen content with increasing age in arteries and veins. The decrease in collagen content was similar in the morphometric and chemical studies and was statistically significant. The thickness of the vessel media did not change significantly with age. The pulmonary artery and vein strips were less extensible in the older age groups, the main change occurring in the elastic phase of the vascular stress/strain curves. It is suggested that changes in the elastic tissue at a molecular and lamellar level are responsible for the increasing stiffness of pulmonary vessels rather than changes in the medial collagen content.

Effects of acute ethanol on the contractile state of normal and failing cat papillary muscles

The direct effects of 100, 300 and 500 mg/100 ml ethanol on contractility of isolated, supported right ventricular papillary muscles were evaluated from 10 normal or failing cat hearts. In isometrically contracting muscles, 500 mg% ethanol decreased maximum tension in normal and failing hearts from 7.1 to 4.3 g/mm2 (P less than 0.001) and 3.4 to 2.3 (P less than 0.01) respectively, and lowered maximum tension rise from 30.4 to 20.2 g/mm2/sec (P less than 0.001) and 10.2 to 0.8 (P less than 0.01), without alterations of time to peak tension. In isotonically contracting muscles, 500 mg% ethanol reduced contractile element velocity at 0.5 g/mm2 load in normal and failing ventricles from 1.27 to 0.97 L/sec (P less than 0.001) and 0.59 to 0.39 (P less than 0.001) respectively. Thus, clinically meaningful doses of ethanol clearly, exerted dose-related negative inotropic actions on both normal and failing myocardium, thereby indicating that ethanol ingestion may exacerbate heart failure in diseased hearts.

Relationship of myocardial infarction to presence of angina pectoris in patients with coronary heart disease: lack of abolition of angina by infarction

To evaluate the relationship between myocardial infarction and angina pectoris, history of symptomatic coronary heart disease was analyzed in 146 patients who had had documented myocardial infarction. There were 126 males and 70 females of mean age 55 years (range 32 to 70 years). Infarction had occurred 6 to 63 months prior to the study (mean: 30 months). Angina pectoris occurred at some time during the clinical course of 75 patients (51%), and 71 patients (49%) had not experienced angina. In the majority of the group with angina (n = 39; 52%) the symptom had not been present before infarction, appearing initially thereafter. Angina was present both before and after infarction in 31 patients (41%). In only 5 patients (7%) was precedent angina lost after infarction. Angina was, therefore, present in 70 of 146 patients (48%) after, compared to 36 patients (25%) before, infarction and in 86% (31/36) of patients with angina before infarction it persisted following the attack. Prior angina following myocardial infarction was not related to increased activity since in the majority of patients activity level was less after than before infarction. Post-infarction cardiac failure, which developed in 9 patients who had prior angina, was not associated with abolition of angina in any of this group. It is concluded that: 1. angina is frequent after myocardial infarction, 2. when present before infarction it usually persists thereafter, 3. angina commonly appears as a new symptom after infarction when not previously present and 4. disappearance of angina after infarction is distinctly uncommon.

Alterations in ventricular mass and performance induced by exercise training in man evaluated by echocardiography

Few data are available regarding the effects of exercise training upon cardiac structure and performance in man. We evaluated the echograms of 24 normals before (PRE) and after (POST) 11 weeks of endurance exercise training. Conditioning consisted of a walk-jog-run protocol at 70% maximal heart rate for one hour four days per week. Training reduced heart rate and increased maximal duration and estimated oxygen consumption of treadmill exercise. Compared to PRE, the echogram in the POST training period revealed an increased left ventricular (LV) end-diastolic dimension (EdD), a decreased end-systolic dimension (EsD) and thus an increased stroke volume (EdD3-EsD3) and shortening fraction (EdD-EsD)/EdD). Cardiac output (CO) and peripheral vascular resistance (BP/CO X 80) were identical PRE and POST conditioning. Importantly, an increase in mean fiber shortening velocity was observed POST training as were increases in LV wall thickness, ECG voltage of S in V1 + R in V5, and LV mass. Thus endurance training was accompanied by increases in both LV dimension and mass as well as LV shortening fraction and contraction velocity as observed by echocardiogram.

Hemodynamic assessment of the new aortic Carpentier-Edwards bioprosthesis

Although glutaraldehyde-preserved porcine aortic Hancock heterografts have lower thromboembolism incidence than mechanical aortic valves, Hancock xenografts provide less functional aortic outflow orifices and thereby greater transvalvular gradients than mechanical prostheses. The newly developed aortic Carpentier-Edwards porcine heterografts comprise a thin-walled Elgiloy flexible metal stent covered with Teflon which provides somewhat wider internal orifices than aortic Hancock valves of the same external annulus diameter. Since aortic Carpentier-Edwards xenografts have not been clinically evaluated previously, the present study assessed cardiac function and heterograft performance (1.7 months postoperation) and clinical status (4.2 months postoperation) of 19 patients with severe aortic stenosis and/or regurgitation prior to surgery. Left ventricular end-diastolic pressures decreased (17 to 9 mm Hg), cardiac index remained normal, and clinical symptomatology diminished markedly. Mean peak transxenograft systolic pressure was only 16 mm Hg (valve area 1.73 cm2), without meaningful regurgitation. Thus aortic Carpentier-Edwards bioprostheses provide generally excellent heterograft function which appears more favorable than previous reports of Hancock xenografts.

Membrane alterations following interferon treatment

Interferon treatment appears to induce a number of changes in the plasma membrane of uninfected cells. Interferon treatment altered the surface exposure of gangliosides of both Ly and KB cell membranes. The differences were found in the amount and pattern of incorporation of tritium after galactose oxidase treatment. In AKR,C- (AKR-2B) mouse cells, not only was there an apparent increase in the number of intramembranous particles in response to treatment with interferon but also the kinetics of the increase followed that of the establishment of the antiviral activity. The buoyant density of plasma membrane was also found to be significantly increased in interferon-treated cells. Moloney murine leukemia virus produced in interferon-treated mouse thymus and bone marrow cells had a high particle to infectivity ration. This virus contained a prominent glycoprotein with a molecular weight of about 85,000. This large glycoprotein was only a very minor component of Moloney leukemia virus produced in control TB cells and might be an uncleaved precursor to gp 69-71.

Effects of digitalis on the exercise electrocardiogram in normal adult subjects

Controversy continues regarding the effects of administration of digitalis upon the exercise electrocardiogram. Thus, maximal treadmill exercise tests were performed before and two weeks after administration of 0.25 mg of digoxin daily in 15 normal subjects (documented by cardiac catheterization and coronary arteriographic studies). Administration of digitalis induced abnormal findings on exercise tests in all 14 subjects with serum levels of digoxin greater than or equal to 0.5 ng/ml; however, at workloads greater than 75 to 90 percent of maximal predicted heart rate, the changes in the ST segment reverted to a normal configuration in all subjects, thereby providing differentiation of digitalis-induced ST-segment alterations from those due to myocardial ischemia at maximal treadmill stress.

Spontaneous cytomegalovirus mononucleosis with conjunctivitis

Cytomegalovirus (CMV) was isolated from the conjunctiva of a patient with mild unilateral catarrhal conjunctivitis associated with the typical clinical features of CMV mononucleosis syndrome in a previously healthy adult. The diagnosis was confirmed by a marked rise in the complement fixation antibody titers. Prospective studies are needed to determine the frequency of conjunctival involvement in CMV mononucleosis and the relation, if any, to sporadic cases of conjunctivitis.