Characterization of histamine type 1 receptors on natural suppressor lymphoid cells

Using the radioligand H1 antagonist [3H]pyrilamine, we have characterized the histamine type 1 receptor on cloned murine natural suppressor cells (NS). A single, specific binding site for [3H]pyrilamine exists on these cells. The binding was saturable and reversible by various specific H1 receptor antagonists. The rank order of potency for displacement of [3H]pyrilamine binding from the H1 receptor by H1 receptor antagonists was promethazine = pyrobutamine greater than pyrilamine greater than diphenhydramine greater than chlorpheniramine. The histamine type-2 agonists, impromidine and dimaprit, and antagonists, cimetidine and ranitidine, as well as selected non-histamine agonists, did not displace [3H]pyrilamine from its binding sites on the natural suppressor cells. The data indicate that the theoretical KD was 1.1 +/- 0.3 X 10(-7) M while the measured KD of binding for [3H]pyrilamine was 6.0 +/- 0.8 X 10(-8) M; the maximum binding was 4.13 nM and the number of binding sites/cell was 2.14 +/- 0.29 X 10(6) (N = 3).

Congener derivatives and conjugates of histamine: synthesis and tissue and receptor selectivity of the derivatives

A series of 19 congener derivatives and conjugates of histamine was synthesized and tested to determine whether the ligands would alter the conventional histamine activity in various tissues. The derivatives, which contained either branched or unbranched aliphatic groups, aromatic amide groups, or dipeptides, exhibited affinities for histamine type 1 and/or type 2 receptors that were widely different from the progenitor. The p-trifluoromethyl derivative of histamine with an intermediate chain length of four methylenes (compound 13) was the most potent lymphocytes H2 receptor agonist but was inactive on guinea pig myocardium H2 receptors. The deletion of a single methylene chain (compound 12) from this compound resulted in total loss of its H2 activity on lymphocytes and its H1 activity on aorta. Compound 12 became an exclusive H1 agonist on lymphocytes H1 receptors. The dipeptide conjugate (compound 17) and the aliphatic congener derivative (compound 18), both with four methylenes, retained some of the activity on guinea pig myocardium H2 receptors, but lost their activity on lymphocytes H2 receptors. Therefore, histamine can be modified at sites that are at a distance from the imidazole moiety, resulting in tissue selective histamine receptor agonists.

In vitro pharmacologic activity of congener derivatives and model conjugates of propranolol and practolol

Previous studies in our laboratory suggested that synthetized derivatives of isoproterenol and histamine could create agonists more potent and receptor and/or tissue selective than the parent compound. In the present study we have evaluated the hypothesis that our results with isoproterenol and histamine derivatives could be extended to include beta-adrenergic antagonists. With this purpose in mind, fourteen derivatives of propranolol and practolol were synthesized and tested in four in vitro systems. The congeners and conjugates were tested using biologic assays (blocking of cAMP accumulation) and/or radioligand binding assays in S-49 lymphoma cells and in rat adipocytes, heart and lung which contain beta 1 and/or beta 2 receptors. Our results indicate that structural modifications distant from the pharmacophore alter the pharmacologic profile of the parent compound. The relative potencies of the derivatives were dependent upon several key factors including the length of the methylene spacer chain and the nature of the substituents on the aromatic ring. The presence of a spacer group with four methylenes resulted in the most active compound in each series when tested on S-49 cells. The derivatives with a paramethyl toluidide group were more potent than the derivatives with a trifluoromethyl toluidide group. The dipeptide derivatives were more potent on adipocyte than S-49 cells, suggesting a preference for beta 1 receptors. Some of the same modifications that led to altered potency and which resulted in an increased receptor and/or tissue selectivity using the progenitors isoproterenol or histamine did extrapolate to the beta blockers. Our data suggest that alterations in receptor and/or tissue selectivity must be imparted by the carrier moiety of the drug and may be related to the biochemical microenvironment of the receptors.

Myocardial infarction and primary ventricular fibrillation after glue sniffing

Images

Conjugates of catecholamines. VII. Synthesis and beta-adrenergic activity of peptide catecholamine conjugates

A series of novel catecholamine derivatives has been prepared in which one of the N-methyl substituents of isoproterenol has been extended by a spacer consisting of a chain of four methylenes which terminates with an amide linkage to a peptide, the point of attachment being via the aromatic amino group of p-aminophenylalanine. In one of the derivatives, two catecholamines are attached to the same peptide in this manner. The peptides, which range in size from three to eight amino acid residues and contain phenylalanine, glycine, and L-alpha-amino-delta-hydroxyvaleric acid, were synthesized via stepwise and fragment condensation techniques. The beta-adrenergic agonist activities of the derivatives were evaluated in vitro by measuring the intracellular accumulation of cyclic AMP in S49 mouse lymphoma cells.

Effects of glucose transport on the incorporation of 32P-inorganic phosphate into phospholipids in Hymenolepis diminuta (Cestoda)

1. The absorption of glucose and alpha-methyl-D-glucoside by Hymenolepis diminuta was concentration dependent. 2. alpha-Methyl-D-glucoside competitively inhibited glucose absorption and was not metabolised by the parasite. 3. alpha-Methyl-D-glucoside significantly lowered (P less than 0.05) the incorporation of 32Pi into all phospholipid classes. 4. Glucose inhibited (P less than 0.01) 32Pi incorporation into phosphatidylcholine only. 5. Phlorizin did not affect 32Pi labelling of phospholipids. 6. Serotonin and histamine stimulated (P less than 0.01) 32Pi labelling of all phospholipid classes. 7. Radioactivities in water soluble fractions were increased (P less than 0.01) in the presence of glucose, serotonin and histamine.

Regulatory effects of mast cells on lymphoid cells: the role of histamine type 1 receptors in the interaction between mast cells, helper T cells and natural suppressor cells

We have investigated the role of mast cells as modulators of lymphocyte function because the mast cells are concentrated in the areas of lymphoid storage; they are dependent upon T-cell growth factor for their proliferation; and they appear to be the principle if not sole storage site for histamine. We have tested the influence of mast cells on the proliferation of alloreactive cloned helper T cells, mixed leukocyte reactions, and the suppressive capacity of natural suppressor cells. We used an IL-3-dependent mast cell line that at high numbers (greater than 10(5)) suppressed and at low numbers (10(3) to 6 X 10(4)) augmented the proliferation of TH cells. Addition of histamine to cocultures enhanced the mast cell mediated proliferation of TH cells without directly affecting the helper cells. The action of histamine appeared to be mediated with H1 type receptors on these mast cells. Pretreatment of natural suppressor cells with supernatants from mast cell enhanced their suppressive capability. Here too, histamines enhanced suppression by the NS cell via histamine type 1 receptors on the natural suppressor cells. Our data suggest that mast cells may be a major modulator of the lymphoid cell immune function and demonstrate a role of histamine type 1 receptors in the interaction between mast cells, helper T cells, and natural suppressor cells.

High potency congeners of isoproterenol. Binding to beta-adrenergic receptors, activation of adenylate cyclase and stimulation of intracellular cyclic AMP synthesis

The potency of a p-toluide derivative and a p-trifluoromethyl derivative of isoproterenol on the beta1 receptor of turkey erythrocytes and on the beta2 receptor of S49 lymphoma cells was measured in comparison with isoproterenol. Binding assays showed that the p-trifluoromethyl derivative possessed an affinity for the receptor, which was two hundred times higher than that of isoproterenol, in the case of turkey erythrocytes, and sixty times higher in the case of the S49 cells. By measuring the Kact of adenylate cyclase, the activity of the p-trifluoromethyl derivative was thirty to forty times higher than that of isoproterenol for the turkey erythrocyte membrane as well as for the S49 lysed cells. In stimulation of intracellular cyclic AMP accumulation, the Kact showed that the p-trifluoromethyl derivative was forty and twenty times more active than isoproterenol in turkey erythrocytes and in S49 cells, respectively. The p-toluide derivative gave similar results. The superior affinity of the above isoproterenol congeners for both beta 1 and beta 2 adrenergic receptors makes these compounds excellent candidates for use as labeled agonist ligands in studies of beta receptors. The possibility is discussed that the relatively large substituent on the amino group of the catecholamine congeners might perhaps bind to lipids associated with the receptor.

Synthetic analogs of cholecystokinin terminal tetrapeptide that stimulate insulin but not glucagon release from pancreatic islets

Two synthetic analogs of CCK-4, Glp-Met-Asp-Phe-NH2 (I) and Pro-Met-Asp-Phe-NH2 (II) reported earlier to stimulate insulin release from the isolated rat pancreatic islets in vitro at concentrations as low as 10(-10) M, have now been found to be totally ineffective as glucagon releasers at concentrations as high as 10(-6) M or higher. It is evident that the replacement of Trp in CCK-4 by Glp and Pro residues leads to peptides which exhibit insulin releasing activity without stimulating the release of glucagon.

The effects of derivatives of histamine on natural suppressor cells

Histamine is an impressive modulator of immune functions at least via its effects on lymphoid cells. Its in vivo effects will not be used practically as long as they produce the profound cardiovascular and pulmonary effects for which the drug is known. A series of 13 congener derivatives and conjugates of histamine was constructed and was tested to investigate whether chemical alterations would result in pharmacologic actions on leukocytes that were more potent and effect specific than histamine. The new compounds, which contained spacer groups of varying lengths between ligand and carrier and with various aromatic modifying groups, showed potencies widely different from histamine when tested in natural suppressor cells. Some compounds showed selective effects on natural suppressor cells in that they were inactive on myocardial tissue, whereas other compounds were selectively active on the myocardium. Some compounds augmented the suppressive capacity of natural suppressor cells in mixed leukocyte reactions via H1 receptors. Our scheme might be more widely extrapolated to other low m.w. immune modulators in an attempt to make them lymphocyte specific. The data also encourage the in vivo testing of selected histamine analogues as selective modulators of immunity. Some of these modulators might be experimentally useful in vivo because they may lack actions in other tissues.

The effects of derivatives of histamine on natural suppressor cells

Histamine is an impressive modulator of immune functions at least via its effects on lymphoid cells. Its in vivo effects will not be used practically as long as they produce the profound cardiovascular and pulmonary effects for which the drug is known. A series of 13 congener derivatives and conjugates of histamine was constructed and was tested to investigate whether chemical alterations would result in pharmacologic actions on leukocytes that were more potent and effect specific than histamine. The new compounds, which contained spacer groups of varying lengths between ligand and carrier and with various aromatic modifying groups, showed potencies widely different from histamine when tested in natural suppressor cells. Some compounds showed selective effects on natural suppressor cells in that they were inactive on myocardial tissue, whereas other compounds were selectively active on the myocardium. Some compounds augmented the suppressive capacity of natural suppressor cells in mixed leukocyte reactions via H1 receptors. Our scheme might be more widely extrapolated to other low m.w. immune modulators in an attempt to make them lymphocyte specific. The data also encourage the in vivo testing of selected histamine analogues as selective modulators of immunity. Some of these modulators might be experimentally useful in vivo because they may lack actions in other tissues.

Beta-adrenergic receptors on human suppressor, helper, and cytolytic lymphocytes

Using the radioligand beta-adrenergic blocker [125I]cyanopindolol (ICYP), we have characterized the beta-adrenergic receptors on Leu 3+ (T helper [TH]), Leu 2+, 9.3- (T suppressor [Ts]) and Leu 2+, 9.3+ (T cytolytic [Tc]) subsets of human lymphocytes. Peripheral blood T cells were isolated by rosetting, and then subsets were purified by their affinities to monoclonal antibodies against their Leu 3 and 9.3 markers. ICYP binding to the subsets was saturable with time and with concentration; the binding was stereoselective and reversible by beta-adrenergic antagonists. A biological response produced by beta agonists increased intracellular concentrations of cAMP and corresponded to the number of binding sites. Each subset of cells had a number of binding sites, which was characteristic for the given subset. The data indicate that the density of distribution of beta-adrenergic receptors was not homogeneous on the precursors of phenotypically and functionally distinct T cells (Ts approximately 2900, Tc approximately 1800 and TH approximately 750 binding sites). The displacement studies using beta-adrenergic agonists were performed on the cytolytic and suppressor T cell subsets, suggesting that the receptors were mainly of the beta-2 type. The immunobiological significance of such selective distribution of numbers and subtypes of beta-adrenergic receptors on distinct T cell subsets is under investigation.

High dose intravenous streptokinase in acute myocardial infarction--short and long term prognosis

Streptokinase (1 million international units) was given intravenously over 30 or 60 minutes to 50 patients four hours or less after the onset of acute myocardial infarction. All were aged less than or equal to 70 years and had 4 mm or greater ST segment elevation in anterior or inferior leads. Rapid (mean 95 min) ST segment resolution, which was taken to indicate reperfusion of the myocardium, occurred in 36 (72%) patients. In these 36 the average time from onset of symptoms to peak creatine kinase, creatine kinase MB, and myoglobin was 9.45 hours, whereas it was 17 hours in the 14 patients in whom indirect criteria did not indicate reperfusion. Reperfusion arrhythmias were invariably present and ventricular tachycardia developed in five patients and ventricular fibrillation in two. The infarct related artery was seen to be open in 28 (70%) of the 40 patients who had delayed coronary arteriography. The frequency of patency in the infarct related artery was no different in patients given streptokinase less than 2 hours or between 2-4 hours from onset of symptoms nor did it differ when streptokinase was infused over 30 or 60 minutes. Mean left ventricular ejection fraction was 57% in those with a patient infarct related artery and 48% in those with an occluded vessel. Eight patients subsequently underwent elective percutaneous transluminal coronary angioplasty after successful thrombolysis and six had coronary artery bypass grafting. There were nine in-hospital reocclusions of the infarct related coronary arteries. Two bleeding episodes occurred; one required transfusion. Five of the 50 patients died in hospital. All of them had had an anterior myocardial infarction; four had bifascicular block and one had right bundle branch block. During follow up, four patients died, two suddenly and two from reinfarction. During follow up (mean 15 months) the frequency of reinfarction, dyspnoea, and angina was low and there was no difference in the proportions of patients returning to work between those with an open infarct related artery and those with a closed infarct related artery. Intravenous administration of high dose streptokinase to selected patients during the acute phase of myocardial infarction is a safe, effective, and practical method of thrombolysis. It must, however, be followed by coronary arteriography to select those patients in whom percutaneous transluminal coronary angioplasty or coronary artery bypass grafting will be helpful.

Heart failure associated with infective endocarditis. A review of 40 cases

Thirty one (78%) of 40 consecutive patients (aged 13-79, mean 44 years) with infective endocarditis had congestive heart failure at presentation. Twenty six (65%) had had rheumatic heart disease and 17 (43%) patients had prosthetic valves. Eight (20%) patients had undergone dental procedures within three months of presentation. Blood cultures were positive in only 22 (55%) of the patients. In nine (41%) of them streptococci of the viridans group were isolated and in seven (32%) patients endocarditis was due to Staphylococcus aureus. Eight patients had Q fever endocarditis. Sixteen patients required operation because of haemodynamic deterioration while they were in hospital; 11 patients had native valves and five had prosthetic valves. Seven had emergency operations and were pyrexial at that time. Four of the seven died in hospital. Of the 12 who were alive and well after surgery only two required further surgery two and three years after the initial operation. Twelve (30%) of the 40 patients died in hospital; in 10 death was mainly due to left ventricular failure or congestive heart failure. All patients died who had renal failure (four cases), myocardial infarction (two cases), complete heart block (one case), or ventricular fibrillation (two cases) before operation. Six (33%) of the 18 patients with culture negative endocarditis died. Two of the four patients seen and treated more than 12 weeks after the onset of symptoms died, as did three of the five patients with prosthetic valves who required surgery while in hospital. Three patients with neurological complications survived and only two (29%) of the seven patients with blood cultures that were positive for Staphylococcus aureus died. Of these 40 high risk patients optimal antibiotic treatment and early surgery for haemodynamic difficulty ensured that 28 (70%) were discharged from hospital alive and well.

The effects of autacoids on cloned murine lymphoid cells: modulation of IL 2 secretion and the activity of natural suppressor cells

The pharmacologic effects of histamine and isoproterenol (autacoids) were studied on clones of murine T helper (TH) and natural suppressor (NS) cells. The data are consistent with receptors for the autacoids being nonrandomly distributed on phenotypically and functionally distinct clones. The effects of histamine on IL 2 secretion by TH cells could be either inhibitory or stimulatory, depending on the conditions of incubation with the autacoid. When TH cells were pretreated with histamine, their secretion of IL 2 was augmented; conversely, if histamine was added to the TH cells in the presence of antigen, IL 2 secretion was inhibited. The suppressor function of NS cells was enhanced by preincubation with histamine (10(-4) M) for 4 hr before the washed NS cells were added to responder and stimulator cells in mixed lymphocyte cultures. Two H1 receptor antagonists, mepyramine (10(-6) M) and pyrobutamine (10(-7) M), each competitively blocked the histamine activation of the NS cells, but an H2 receptor antagonist cimetidine (10(-5) M) did not alter the suppressor-enhancing function of histamine. Activation of NS cells did not occur if histamine was added with responder, stimulator, and co-cultured cells in MLR. The effects of each autacoid were additive in cytolytic T cells alone. The adenylate cyclase pools that can be stimulated by isoproterenol and histamine in cytolytic T cells may be independent of each other, but further work will be needed to prove this point.

The effects of autacoids on cloned murine lymphoid cells: modulation of IL 2 secretion and the activity of natural suppressor cells

The pharmacologic effects of histamine and isoproterenol (autacoids) were studied on clones of murine T helper (TH) and natural suppressor (NS) cells. The data are consistent with receptors for the autacoids being nonrandomly distributed on phenotypically and functionally distinct clones. The effects of histamine on IL 2 secretion by TH cells could be either inhibitory or stimulatory, depending on the conditions of incubation with the autacoid. When TH cells were pretreated with histamine, their secretion of IL 2 was augmented; conversely, if histamine was added to the TH cells in the presence of antigen, IL 2 secretion was inhibited. The suppressor function of NS cells was enhanced by preincubation with histamine (10(-4) M) for 4 hr before the washed NS cells were added to responder and stimulator cells in mixed lymphocyte cultures. Two H1 receptor antagonists, mepyramine (10(-6) M) and pyrobutamine (10(-7) M), each competitively blocked the histamine activation of the NS cells, but an H2 receptor antagonist cimetidine (10(-5) M) did not alter the suppressor-enhancing function of histamine. Activation of NS cells did not occur if histamine was added with responder, stimulator, and co-cultured cells in MLR. The effects of each autacoid were additive in cytolytic T cells alone. The adenylate cyclase pools that can be stimulated by isoproterenol and histamine in cytolytic T cells may be independent of each other, but further work will be needed to prove this point.

Pharmacologic effects of autacoids on subsets of T cells. Regulation of expression/function of histamine-2 receptors by a subset of suppressor cells

Autacoids (principally histamine, beta adrenergic catecholamines, and prostaglandins E and A) have only recently been recognized as substantive moderators of a number of immune functions. If autacoids are to be considered as potential therapeutic immunomodulators, it is necessary to understand their effects on subsets of T cells while they are and are not in contact with each other. This report demonstrates that autacoid receptors are nonrandomly distributed on phenotypically and functionally distinct subsets of human T cells. Each human T cell subset responded to both histamine and isoproterenol, but the dose response curve and maximal efficacy varied widely between the subsets. The suppressor T cells were more responsive to both histamine and isoproterenol than helper/inducer T cells (TH) or cytotoxic T cells (Tc). We found that after mitogenic stimulation the response to histamine, but not isoproterenol, was greatly increased only in TH (Leu 3+) and Tc (Leu 2+, 9.3+) subsets, and that this effect may be regulated by suppressor T cells (Leu 2+, 9.3-). The dramatic rise in cAMP accumulation in response to histamine in mitogen-treated TH and Tc was totally blocked by an H2 antagonist (cimetidine), but not by an H1 antagonist (mepyramine). These findings indicate interdependence of (a) immunologically uncommitted subsets in their response to selected drugs, and (b) control of basal- and autacoid-induced cAMP production, as well as (c) increased qualitative and quantitative selectivity, which is caused by mitogen. If we had performed these experiments only on unseparated cells we would not have observed the remarkable selectivity of autacoid effects on subsets of T cells.

Immunoregulatory T cells in man. Histamine-induced suppressor T cells are derived from a Leu 2+ (T8+) subpopulation distinct from that which gives rise to cytotoxic T cells

One mechanism of histamine-mediated inhibition of the immune response in man is to activate T suppressor cells that bear the Leu 2 (OKT8) marker. The current study was undertaken to characterize the histamine-induced suppressor cell using a monoclonal antibody (9.3) shown previously to distinguish cytotoxic T cells from antigen-specific suppressor T cells. Leu 2+ cells isolated from peripheral blood were further separated with antibody 9.3 into Leu 2+, 9.3+, and Leu 2+, 9.3- subsets and each subset was incubated with different concentrations of histamine before determining their ability to suppress immune responses in vitro. The results indicate that the Leu 2+, 9.3- subpopulation includes all histamine-induced suppressor cells, that 10(-4) M histamine is the optimal concentration for suppressor cell induction, and that exposure of Leu 2+, 9.3- cells to histamine for 30 s is sufficient to initiate the induction process. After treatment with histamine these cells inhibit both phytohemagglutinin-induced T cell proliferation and pokeweed mitogen-induced B cell differentiation. The suppression of phytohemagglutinin-induced proliferation was resistant to x-irradiation with 1,200 rad, either before or after histamine exposure, suggesting that Leu 2+, 9.3- cells need not proliferate to become suppressor cells or exert suppression. Moreover, suppression by these cells was not due to altered kinetics of the response. Finally, a histamine type 2 receptor antagonist (cimetidine) but not a type 1 receptor antagonist (mepyramine) blocked the induction of suppressor cells. On the basis of these results and our previous studies of antigen specific suppressor cells, we conclude that Leu 2+ suppressor cells in man are derived from a precursor pool that is phenotypically distinct from cells that can differentiate into cytotoxic T cells.

Effect of age on Agaricus bisporus PHA-B stimulated insulin release and 45Ca2+ uptake in vitro by islets of Langerhans

The in vitro basal insulin release and 45Ca2+ uptake by rat islets of Langerhans remain unaffected by the animal's age. However, when Agaricus bisporus lectin PHA-B is added to the medium, there is a significant stimulation of basal insulin secretion and 45Ca2+ uptake. The islets isolated from younger rats are more sensitive to A. bisporus PHA-B stimulation and register 1.5-fold and 3-fold more increases of insulin release and 45Ca2+ uptake respectively as compared to islets isolated from 12-month-old rats. Age-related conformational changes in the B-cell membrane are suggested as a possible explanation for the above observation.

Trace element levels in human alcoholic brain

Copper, magnesium, zinc and manganese levels in the temporal cortex of human alcoholic and control brains were measured by atomic absorption spectrophotometry using both the flame and graphite furnace. All of the 21 alcoholics were male with a mean age of 54.1 years; the 19 male controls had a mean age of 60.2 years. The only statistically significant change in ion levels was an increase in manganese concentration (expressed both as microgram/g wet weight and ng/mg protein) in the alcoholic group when compared to the control group. Five of the alcoholics had malignancies, while 16 of the controls had systemic malignancies. Covariance analysis showed there was no effect of age on the level of manganese in the temporal cortex.

A study of ocular complications in leprosy

A total of 380 leprosy patients were studied in four different leprosy hospitals. The involvement of eye was found in 18.95% of cases in which 10.97% in lepromatous leprosy and 8.16% in non-lepromatous leprosy cases. In total cases studied 52.63% were of lepromatous leprosy and 47.37% of non lepromatous leprosy cases. Among them 11.05% were males and 18.95% were females. In 72 cases of ocular involvement, males constituted 80.56% and females 19.44% of cases. Maximum cases (52.78%) of ocular involvement were in leprosy patient with 5 to 10 years of duration. Blindness among the total leprosy patients studied was 1.84% which was mainly due to corneal opacity following exposure keratitis and ulceration, iridocyclitis and its complications.

Group C streptococcal endocarditis associated with intubation-induced tracheal stenosis

We describe a 44-year-old woman with Group C haemolytic streptococcal endocarditis who developed tracheal stenosis as a result of endotracheal intubation. She recovered fully following valve replacement for continuing left ventricular failure due to mitral and aortic incompetence and subsequent resection of the stenosed tracheal segment with reanastomosis of the trachea.

Microvascular abnormalities as possible predictors of disease subsets in Raynaud phenomenon and early connective tissue disease

In vivo capillary examination was performed on 80 patients included in a prospective study of Raynaud phenomenon (RP): 40 RP only (RPO), 20 undifferentiated connective tissue disease (UCTD) and 20 systemic scleroderma (SD) of less than 5 years' duration. On initial examination, SD-pattern capillary abnormalities were found in 7/40 patients with RP alone, 18/20 with UCTD and 19/20 with SD. On follow-up a change of diagnosis into a definite connective tissue disease occurred in 4 patients with UCTD; one patient with RP alone died with symptoms of myositis and fulminant pulmonary vasculitis. All five showed SD-pattern capillary abnormalities of the "active" type on initial examination. A significant correlation between the "slow" capillary pattern and the presence of anticentromere antibodies was also observed. Only one patient of 25 RPO with normal capillaries available for follow-up showed any change in clinical status.

Clinical, echocardiographic, and operative findings in active infective endocarditis

Images

Discrete subaortic stenosis

Data concerning 17 consecutive patients with discrete subaortic stenosis are recorded. Twelve patients underwent operative resection of the obstructing lesion. Of these all except one were symptomatic and all had electrocardiographic evidence of left ventricular hypertrophy or left ventricular hypertrophy with strain. They had a peak resting systolic left ventricular outflow tract gradient of greater than 50 mmHg as predicted from the combined cuff measurement of systolic blood pressure and the echocardiographically estimated left ventricular systolic pressure and/or as determined by cardiac catheterisation. The outflow tract gradient as predicted from M-mode echocardiography and peak systolic pressure showed close correlation with that measured at cardiac catheterisation or operation. During the postoperative follow-up from one month to 11 years, of 11 patients, one patient required a further operation for recurrence of the obstruction four years after the initial operation. All patients are now asymptomatic. Five patients have not had an operation. The left ventricular outflow tract gradient as assessed at the time of cardiac catheterisation was greater than 50 mmHg. One patient has been lost to follow-up. The remaining four have been followed from four to eight years and have remained asymptomatic and the electrocardiograms have remained unchanged. Careful follow-up of all patients is essential with continuing clinical assessment, electrocardiograms, M-mode and two-dimensional echocardiograms, and if necessary cardiac catheterisation. Prophylaxis against bacterial endocarditis is also essential.

Myopathy and external pulmonary artery compression caused by sarcoidosis

Images

Management of recurrent ventricular tachyarrhythmias associated with Q-T prolongation

Eleven patients with acquired prolongation of the Q-Tc interval and recurrent ventricular tachyarrhythmias were studied. Five patients required 5 to 44 direct current shocks to correct prolonged ventricular tachyarrhythmias, and five were given at least two antiarrhythmic agents in an attempt to control the arrhythmias. In 4 of the 11 patients, when thioridazine, diuretic drugs and antiarrhythmic agents were withdrawn and hypokalemia or hypocalcemia corrected, ventricular tachyarrhythmias did not recur. The Q-Tc interval normalized in 2 to 3 days. Ventricular tachyarrhythmias were recurrent in the remaining seven patients, despite withdrawal of the drugs that caused the Q-Tc prolongation, attempted correction of hypokalemia when present and the administration of antiarrhythmic agents to four of the seven. All antiarrhythmic agents were then withdrawn in this group. Immediately on the establishment of overdrive ventricular or atrioventricular sequential pacing in these patients, ventricular tachyarrhythmias were abolished. No breakthrough ventricular tachyarrhythmias occurred during temporary pacing. Temporary pacing was required for an average of 10 days and the Q-Tc interval normalized an average of 5 days from the onset of pacing. Three patients required a permanent pacemaker, one because of chronic complete heart block, one because of the sick sinus syndrome, and one because of frequent ventricular ectopic complexes complicating ischemic heart disease. All 11 patients survived their period of hospitalization.

Management of ventricular septal rupture in acute myocardial infarction

Four patients with rupture of the interventricular septum after myocardial infarction are described. This condition carries a grave prognosis. Surgical repair of the septum is almost always urgently required if the left-to-right shunt is large (QP/WS > 3). Results are better if surgery can be deferred for six weeks to allow the infarcted area to heal and the tissues to be come firmer. This delay may be achieved by using a combination of agents to reduce afterload and to exert a positive inotropic effect. The timing of surgical intervention was an important factor in the survival of three of the four patients.

Actinomycin D binds with highest affinity to nonribosomal DNA

Based on previous evidence (T.J. Lindell (1976) Nature 263, 347-350 and T.J. Lindell, A.F. O'Malley, and B. Puglisi (1978) Biochemistry 17, 1154-1160) it was anticipated that actinomycin D in a low concentration would bind to DNA which is involved in the regulation of rRNA transcription in eukaryotes. This was examined by digestion of rat (liver) DNA with EcoRI, adding [3H]actinomycin D (0.004 microgram/ml) and resolution of the restriction fragments by RPC-5 chromatography. Labeled actinomycin D was found to bind with highest affinity to a single fraction consistently eluting at 0.63 M KCl. A similar digestion and fractionation of nucleolar DNA, which is enriched in rDNA sequences, did not reveal a similar high affinity binding of actinomycin D. This fraction of DNA which binds actinomycin D with highest affinity did not contain any rDNA as evidenced by hybridization with [32P]rRNA. Therefore, at the concentration of 0.004 microgram/ml, actinomycin D does not selectively bind to rDNA as evidenced by two independent criteria. Whether this high affinity actinomycin D-binding DNA has any function in the regulation of rRNA transcription remains to be determined.

Comparative study of atropine and glycopyrrolate on suxamethonium-induced changes in cardiac rate and rhythm

The effectiveness of atropine and glycopyrrolate in the prophylaxis of suxamethonium-induced bradycardia was evaluated in a double-blind study of 56 patients. Three had clinically demonstrable bradycardia, all having received atropine. We conclude that glycopyrrolate offered adequate protection against cardiac effects of repeated doses of suxamethonium.

Factors related to the intention to have additional children in the United States: a reanalysis of data from the 1965 and 1970 national fertility studies

Reproductive intentions of white mothers with no more than three children in 1965 and in 1970 were analyzed for their stability and change with respect to such factors as parity, age of the youngest child, wife's employment, and husband's education. Parity and age of the youngest child were found to have a much more important effect on the intent to have additional children than were such socioeconomic variables as wife's employment and husband's education. Parity and the interval since the latest birth (or the age of the youngest child) were found to have a nonlinear effect and to interact in affecting the reproductive intention. This suggests a convergence to a two-child family as the threshold size and that the lenght of childspacing is contingent on the parity. Change during 1965--1970 in this direction was found to be greater among mothers with husbands having college or higher educations.

Cephalothin induced neutropenia during the treatment of bacterial endocarditis

The occurrence of cephalothin induced neutropenia in 3 patients with infective endocarditis is described. In each patient, withdrawal of cephalothin was followed by rapid haematological recovery. It is apparent that granulocytopenia may frequently occur in patients receiving prolonged, high dose, intravenous cephalothin for the treatment of bacterial endocarditis.

Causes of clinic drop-out among Iranian pill users

A national study of the Iran family planning programme is yet to be undertaken. This paper reports clinic continuation rates and causes of drop-out among Iranian pill acceptors based on patient records at three selected clinics in Shiraz and Marvdasht. All three clinics were shown to have a cumulative continuation rate of over 50% up to 1 year. Causes of clinic drop-out varied between rural and urban pill users by time of acceptance and by the acceptors’ background characteristics. The probability of drop-out for unreported reasons was related to level of motivation. The effect of follow-up by clinic motivators was clearly demonstrated in the temporal pattern of drop-out among rural acceptors. The probability of drop-out for medical side effects was related to knowledge about them and users’ own experience. Risk of accidental pregnancy was seen to reduce as pill users gained experience.

Polyradiculoneuritis and Mycoplasma pneumoniae infection

A patient with severe Mycoplasma pneumonia developed polyradiculoneuritis and respiratory failure. The acute phase of the illness was complicated by a myocarditis, and recovery of neurological function was slow. Residual left hemidiaphragmatic paralysis was present 1 year after onset of the illness.

An outbreak of dysentery caused by Shigella dysenteriae type 1 on a coral island in the Bay of Bengal

An epidemic of severe dysentery occurred on St. Martin Island in the Bay of Bengal at a time when the island, with a population of 1,318, was isolated from the mainland because of the monsoon season. There were 434 cases and 28 deaths within a three-month period. Mortality (2%) was limited to the very young and the elderly. Shigella dysenteriae type 1 (Shiga bacillus) was isolated from 12 of 65 rectal swab specimens. All strains gave similar biochemical reactions and were resistant to tetracycline, chloramphenicol, streptomycin, and the sulfonamides but were sensitive to ampicillin, kanamycin, and gentamicin. No other organism was implicated in the outbreak. The disease disappeared from the island after institution of chlorination of the sources of drinking water and effective treatment of patients.