Co-engagement of CD3 with LFA-1 or ICAM-1 adhesion molecules enhances the frequency of activation of single murine CD4+ and CD8+ T cells and induces synthesis of IL-3 and IFN-gamma but not IL-4 or IL-6.

Interaction between the cell adhesion molecules lymphocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) augments T cell activation by increasing the avidity of T cell/antigen-presenting cell (APC) binding. To examine whether LFA-1 and ICAM-1 can also contribute to T cell activation in the absence of APCs, single murine CD4+ and CD8+ T cells were cultured with IL-2 and immobilized antibodies to CD3, CD4 or CD8, and LFA-1 or ICAM-1. The combination of anti-CD3, anti-CD4/CD8, and IL-2 stimulated approximately 20% of CD4+ cells and 30% of CD8+ cells to proliferate. Inclusion of anti-ICAM-1 antibody increased these frequencies to 30 and 40% respectively. Maximum activation frequencies were obtained with the combination of anti-CD3, anti-CD4/CD8, and anti-LFA-1 which stimulated cell division by approximately 40% of single CD4+ cells and at least 60% of single CD8+ cells. Under these conditions, 30-40% of the resultant CD4+ clones and greater than 90% of CD8+ clones secreted IL-3 and IFN-gamma. In addition to responding at higher frequencies that CD4+ cells, CD8+ cells formed larger clones which produced 4-fold higher levels of both cytokines. Although the expression of IL-2, IL-3, IFN-gamma, granulocyte-macrophage colony stimulating factor and tumor necrosis factor alpha could be detected in CD4+ and CD8+ clones at the mRNA level following reverse transcription and polymerase chain reaction amplification, neither the secreted nor mRNA expression of IL-4 or IL-6 was detected in any of the tested clones. It is concluded that co-stimulation of T cells via LFA-1 or ICAM-1 can enhance T cell receptor-dependent activation in the absence of accessory cells and that this mode of stimulation leads to the expression of a restricted range of cytokine genes.


In utero treatment with monoclonal antibody to IL-2 receptor beta-chain completely abrogates development of Thy-1+ dendritic epidermal cells.

Interleukin-2 (IL-2), a crucial growth factor for mature T lymphocytes, is produced in fetal thymus under developmental control, although its biological significance remains unclear. We found that the two distinct subunits of the IL-2 receptor, i.e. the alpha-chain (IL-2R alpha) and the beta-chain (IL-2R beta), were expressed in an almost mutually exclusive fashion throughout fetal thymus ontogeny, and that the blockade of IL-2R beta, a signal transducing component of IL-2R, by administering a neutralizing mAb to IL-2R beta resulted in the complete and selective disappearance of Thy-1+ skin dendritic epidermal cells. Development of any other T cell subsets was uncompromised. This indicates that IL-2 plays a crucial role in the development of fetal V gamma 5+ cells and their descendants.


Identification of an equivalent to murine Thy-1+ dendritic epidermal cells in the rat epidermis.

In the murine epidermis, there exist Thy-1+ dendritic epidermal cells (Thy-1+DEC). These cells are Thy-1+, CD45+, CD3+ and asialo GM1+ but CD5-, CD4-, CD8-, or Ia-1-, and express T cell receptor (TCR) gamma delta. Recently, most of these TCR gamma delta of Thy-1 DEC are shown to consist of a V gamma 3-V delta 1 combination. There has been no evidence that the same type of cell population exists in other species except mice. In this study, we investigated the existence of a Thy-1+DEC equivalent in the rat epidermis. The epidermal sheets obtained from rats were stained with various monoclonal antibodies to rat lymphocytes. We developed a monoclonal antibody (1F4) to rat CD3 complex. 1F4 stained thymocytes and peripheral T cells and also immunoprecipitated T cell receptor with CD3 complex. Using 1F4 and a recently developed monoclonal antibody to rat TCR alpha beta, we could identify dendritic CD4-, CD8-, CD5-, CD3+, TCR alpha beta- cells in the rat epidermis. These CD3+, TCR alpha beta- cells are strong candidates as an equivalent to TCR gamma delta + murine Thy-1+ DEC.


Relation between 25-hydroxyvitamin D3, apolipoprotein A-I, and high density lipoprotein cholesterol.

In a survey of cardiovascular risk factors in 185 men and 173 women of a Belgian population group, an independent and highly significant positive correlation was found between the serum concentrations of 25-hydroxyvitamin D3 and apolipoprotein A-I (p less than 0.001 in both sexes). 25-Hydroxyvitamin D3 also showed a positive correlation with high density lipoprotein cholesterol levels (p less than 0.05 in men and p less than 0.005 in women). This relation was independent of a possible effect of 25-hydroxyvitamin D3 on serum calcium. Taking the biological variation of 25-hydroxyvitamin D3 levels (+/- 2 SD = 25 ng/ml) into account, these findings could explain variations in the levels of apolipoprotein A-I of 15 mg/100 ml and of high density lipoprotein cholesterol of 4 mg/100 ml.


A DNA polymorphism for LCAT is associated with altered LCAT activity and high density lipoprotein size distributions in baboons.

A polymorphic Pvu II site was mapped to intron 5 of LCAT, the gene encoding baboon lecithin: cholesterol acyltransferase (LCAT). In a study of 83 baboons, heterozygous baboons (Pv1/Pv2) had significantly higher LCAT enzyme activity levels than did baboons homozygous for the more common allele (Pv1/Pv1). LCAT genotype explained 6% of the total variation in LCAT enzyme activity. To test for allelic effects on cholesterol metabolism, we compared serum concentrations of high density lipoprotein (HDL) cholesterol and apolipoprotein A-I (apo A-I). We also compared distributions of cholesterol and apo A-I among three HDL size classes (HDL1, HDL2, and HDL3). All measurements were obtained for each baboon after long-term feeding of a basal diet low in cholesterol and fat and again after 7 weeks on an atherogenic diet. Heterozygous baboons had significantly lower serum levels of total cholesterol than did homozygotes. In addition, we detected significant effects of LCAT genotype on size distributions of HDL cholesterol and apo A-I on both diets but did not detect any genotype-by-diet interaction. Heterozygotes had increased amounts of cholesterol and apo A-I in HDL3 particles and lower amounts of cholesterol and apo A-I in the larger HDL size classes by comparison with homozygotes. Overall, the LCAT polymorphism explained a significant proportion of total variation in cholesterol (4-10%) and apo A-I (13%) distributions on both diets. Thus, the results indicate that the LCAT polymorphism is associated with significant differences in LCAT enzyme activity and with alterations in HDL compositions.


Alterations in substrate utilization in the reperfused myocardium: a direct analysis by 13C NMR.

An alternative 13C NMR method which allows direct determination of substrate oxidation in tissue for up to three competing 13C-enriched substrates is presented. Oxidation of competing substrates can be measured by 13C NMR spectroscopy under non-steady-state conditions if the relative areas of the glutamate C3 and C4 resonances can be determined. The accuracy of this measurement is limited during brief exposure to 13C-enriched substrates because of the low enrichment in the C3 carbon. The glutamate C4 resonance from a tissue sample which has oxidized a combination of [1,2-13C]acetate (or a uniformly enriched fatty acid mixture) and [3-13C]lactate appears as a nine-line resonance consisting of four multiplet components: a singlet (C4S), two doublets with differing one-bond coupling constants (C4D34 and C4D45), and a quartet (C4Q). It is shown that the sum of the C4S + C4D34 resonance areas versus the C4D45 + C4Q resonance areas directly reports the relative utilization of [3-13C]lactate versus [1,2-13C]acetate, respectively, regardless of citric acid cycle intermediate pool sizes or carbon flux through anaplerotic reactions. We also show that homonuclear 13C decoupling of the glutamate C2 resonance collapses the C3 resonance multiplet into an apparent triplet (actually, a singlet plus a doublet); the relative area of the singlet component reflects the amount of unlabeled acetyl-CoA entering the cycle. The method has been used to determine the contribution of lactate/acetate/glucose to acetyl-CoA in normoxic and reperfused rat hearts.(ABSTRACT TRUNCATED AT 250 WORDS)


A soluble factor and GTP gamma S are required for Dictyostelium discoideum guanylate cyclase activity.

Amoeba of Dictyostelium discoideum show a rapid, transient cGMP synthesis in response to chemotactic stimulation. Using Mg(2+)-GTP as a substrate, guanylate cyclase (E.C. 4.6.1.2.) activity is found exclusively in the particulate fraction of Dictyostelium cells. Here we show that the activity is dependent on the presence of the non-hydrolysable GTP-analogue GTP gamma S, which itself is only a poor substrate for the enzyme under the prevailing conditions. Evidence is presented that a transient exposure of the enzyme to GTP gamma S is sufficient to constitutively activate the enzyme. GTP gamma S-dependent activity is found to require a factor that can be separated from the enzyme by washing the particulate fraction with low salt buffer. Addition of the soluble cell fraction to these washed membranes restores enzyme activity.


Growth hormone and renal glutamine and glutamate handling.

Growth hormone administration effects a positive nitrogen balance in part by recycling glutamine nitrogen as glutamate at the expense of ureagenesis. The study presented here focuses on the response of the isolated perfused hypophysectomized rat kidney to acute growth hormone administration during infusions of either glutamine or glutamate. Growth hormone at 50 nM acutely decreases the renal utilization of both glutamine and glutamate while enhancing reabsorption of the latter. During glutamine infusions of either 1,000 or 500 nmol/min, growth hormone markedly reduced net glutamine utilization by 55% at the high loads and reversed utilization to release at the lower load; associated with decreased glutamine utilization was reduced ammonium production and increased glutamate release. Although glutamine reabsorption was unchanged, glutamate reabsorption increased and NH4+ excretion decreased. During glutamate infusion of 180 nmol/min, growth hormone reduced glutamate utilization 66%, the residual utilization matching increased glutamate reabsorption was associated with enhanced bicarbonate reabsorption and a redistribution of NH4+ release into the urine; all three responses were eliminated by amiloride. These responses to growth hormone are consonant with reduced glutamate oxidation underlying decreased glutamine utilization and accelerated luminal Na+-H+ exchange mediating luminal transport, events that are conceivably interrelated.


Helper T cell memory: more questions than answers.

The critical participation of helper T cells in immunologic memory of animals is clear. Features of antigen-specific CD4 memory cells in primed animals that distinguish them from naive cells are their increased frequency, their ability to secrete lymphokines in addition to IL-2 and their expression of distinct arrays of surface molecules. The latter include increased CD44, CD45RO, LFA-3 and VLA-4 and decreased CD45RA,B and Mel-14. These differences in surface markers may contribute to increased interaction potential for APC, and to distinct patterns of recirculation, but direct demonstrations of the former have yet to be provided. Other possible distinctions that are also largely hypothetical, include distinct requirements for activation and the ability to respond more rapidly to stimulation. The factors that regulate the development of memory helper T cells are also unknown.


Carrier detection and prenatal diagnosis of hemophilia A: 5-years experience at a hemophilia center.

The identification of carriers and the prenatal diagnosis of hemophilia A have greatly improved with knowledge of the structure of the factor VIII gene. This has permitted the defect to be traced in families by using restriction fragment length polymorphisms. This study summarizes 5 years' experience at A. Bianchi Bonomi Hemophilia and Thrombosis Center and the problems encountered. One hundred and forty-four women at risk of hemophilia A from 93 families were referred to our center for DNA analysis. Carrier detection was performed in 95 women, including 11 who were pregnant. Prenatal diagnosis was performed at 7-14 weeks' gestation in 56 pregnant women. We employed two intragenic restriction fragment length polymorphisms (XbaI and BclI) and the two extragenic restriction fragment length polymorphisms (TaqI and BglII). Combining the results of intra and extragenic restriction fragment length polymorphisms with pedigree analysis, a diagnosis was reached in approximately 90% of cases. Of the 33 male fetuses, 11 were affected and 19 not affected. Two cases of recombination between extragenic restriction fragment length polymorphisms and the factor VIII locus were found.


Didanosine.

To review the chemistry, intracellular metabolism, pharmacokinetics, and clinical experience with didanosine (2',3'-dideoxyinosine [ddI]). English-language articles and conference proceedings (indexing terms were didanosine, 2',3'-dideoxyinosine, and ddI). Available Phase I studies and abstracts determined to have clinical significance were included. Clinical experience with ddI is limited to uncontrolled Phase I studies and a large "expanded-access" program. The primary outcome parameters used to evaluate ddI were the HIV surrogate markers: CD4+ lymphocytes and p24 antigen. Thus, the clinical data reviewed here must be evaluated critically and be considered preliminary until the results of studies comparing ddI with zidovudine (ZDV) and combination studies are available. Didanosine has been approved for the treatment of HIV infection in patients who are unable to tolerate ZDV because of adverse effects (e.g., anemia and neutropenia) or who experience clinical or immunologic deterioration while receiving ZDV. Compared with ZDV, ddI has a long intracellular half-life and negligible bone-marrow toxicity. It also has in vitro activity against ZDV-resistant strains of HIV. Phase I studies indicate that ddI has a beneficial effect on the CD4+ cell counts and HIV p24 antigen concentrations. As a result of the acid-labile nature of ddI, oral formulations are buffered or must be mixed with antacid to neutralize gastric pH. Bioavailability then averages 20-40 percent, depending on the dose and formulation given. The plasma half-life, total body clearance, and volume of distribution of ddI are one to two hours, 0.7-1 L/kg/h, and 0.8-1 L/kg, respectively. Painful peripheral neuropathy and pancreatitis (dose-limiting toxicities of ddI) occurred in 34 and 9 percent of patients in Phase I studies, respectively. Didanosine has demonstrated preliminary efficacy in the treatment of late-stage HIV infection; however, its effect on patient survival, its efficacy relative to ZDV, and its utility in combination with other agents are still under evaluation.


Regulation of total ovarian glutathione content in the rat.

Glutathione (GSH) is an important intracellular thiol capable of altering metabolism following exposure to certain important biologic toxicants including radiation and cyclophosphamide. In order to evaluate the inhibition of glutathione synthesis in the ovary, 30-day-old Sprague Dawley rats were treated with either saline or 0.6 mumol/kg (0.133 mg/kg), 6.0 mumol/kg (1.33 mg/kg), or 4.5 mmol/kg (1000 mg/kg) buthionine sulphoximine (BSO) IP and sacrificed at 0, 1, 2, 4, 6, 8, and 24 h. There was an inhibition of glutathione synthesis with 4.5 mmol/kg (1000 mg/kg) BSO with a nadir at 8 h (P less than 0.001) and complete recovery at 24 h. In the subsequent experiments rats were divided into four groups. All animals received either saline or BSO 4.5 mmol/kg/day (1000 mg/kg/day) from day 27 to 30 of life and either saline or PMSG 5 IU IP on day 29 of life. BSO reduced ovarian content of GSH (saline-saline compared with BSO-saline, P less than 0.0001), which was countered by the prior administration of PMSG (BSO-saline compared with BSO-PMSG, P less than 0.005). Glutathione levels were as follows: saline-saline 4.3 +/- 0.04; saline-PMSG 5.0 +/- 0.4; BSO-saline 2.13 +/- 0.2; BSO-PMSG 3.24 +/- 0.2 nmol/mg ovary. These findings suggest the ovary is susceptible to GSH depletion by in vivo administration of BSO. Gonadotropin (PMSG) is capable of effecting a partial return of total ovarian GSH content.


Effects of carvedilol on adrenergic receptor pharmacology in human ventricular myocardium and lymphocytes.

Carvedilol, a new beta-blocker with vasodilating properties due to alpha 1-blockade, was investigated in preparations of human ventricular myocardium. Carvedilol demonstrated a high affinity and is a slightly beta 1-selective competitive beta-blocking agent, with a KD for beta 1-receptors of approximately 4-5 nM and a mild selectivity for beta 1 vs. beta 2 receptors of 6- to 39-fold, depending on the method employed to assess subtype potency. In addition, carvedilol was also a potent alpha 1-blocking agent, with a beta 1:alpha 1 blocking relative potency of 1.7-fold. In human lymphocytes containing beta 2-receptors and in human myocardial membranes containing both beta 1- and beta 2-receptors carvedilol exhibited the unique property of guanine nucleotide modulatable binding. Despite this, no intrinsic sympathomimetic activity of carvedilol was detected in preparations of isolated human heart or in myocardial membranes. Vasodilation related to alpha 1-blockade and the lack of intrinsic activity should translate into improved tolerability and good efficacy in the treatment of heart failure.


Carvedilol and the kidney.

Antihypertensive drugs have differing effects on renal hemodynamics, tubular function, plasma electrolytes, and hormonal responses. Nonselective beta-blockers without intrinsic sympathomimetic activities, such as propranolol, have been reported to reduce renal blood flow and to cause a modest decrease in glomerular filtration rate. Carvedilol is a new multiple action agent displaying nonselective beta-blockade without intrinsic sympathicomimetic activity, alpha 1-adrenoceptor blockade (probably responsible for its vasodilator activity), and possibly also calcium antagonist properties. The presence of these different pharmacodynamic properties results in a different effect on the kidney as compared with, e.g., propranolol. In the dog, intrarenal infusion of carvedilol resulted in a renal vasodilator response with preservation of renal blood flow and without inducing sodium retention; in contrast, propranolol induced a renal vasoconstrictor response and sodium retention in this model. A renal vasodilator response to carvedilol was also reported in spontaneously hypertensive rats (SHR) and in DOCA-salt SHR. In contrast to labetalol, i.v. infusion of hypotensive doses of carvedilol in conscious SHR did not cause sodium retention. Carvedilol was effective in controlling hypertension and preserving renal function in a rat model of progressive hypertensive renal disease. In patients with essential hypertension, carvedilol was reported to reduce renal vascular resistance in the presence of reduced perfusion pressure, allowing for normal renal autoregulation of renal blood flow. Although a small reduction in glomerular filtration rate was seen after acute administration, renal function was preserved during chronic treatment. It is concluded from these studies that renal perfusion and renal function are well maintained during acute and chronic treatment with carvedilol.(ABSTRACT TRUNCATED AT 250 WORDS)


Pharmacological profile of beta-adrenoceptor blockers with vasodilating properties, especially carvedilol--rationale for clinical use.

The rationale for the combined use of beta-adrenoceptor antagonists and vasodilators is to improve the efficacy of the antihypertensive therapy and to reduce the incidence of side effects. If suitable coagents are selected and used at appropriate doses, the disadvantages of each separate component (compromised blood flow to individual organs, increase in total peripheral resistance, unfavorable lipid profile for beta-blockers; stimulation of counter-regulatory mechanisms, retention of water and electrolytes for vasodilators) can be balanced. In addition, the favorable effects of each (reduction in cardiovascular morbidity and mortality for beta-blockers, and favorable hemodynamic profile for vasodilators) may be used to advantage. Such a treatment rationale can be accomplished by a free combination or by using a dual-acting drug. From the practical point of view, the latter may be preferable. The basic requirement for such a drug is that the two effects are evoked in the same dose range. Carvedilol is a dual-acting drug designed to produce beta-blockade and vasodilation in the same dose range. The vasodilation is mediated predominantly by specific alpha 1-adrenoceptor blockade; at markedly higher concentrations additional vasodilating actions can be observed. These effects resemble those of Ca(2+)-antagonistic properties. However, they do not contribute to the acute blood-pressure-lowering activity, but may be responsible for the increased blood flow to some organs. At beta-blocking doses, carvedilol reduces the total peripheral resistance, and blood flow to the kidneys is preserved. Cardioprotection has been demonstrated in a variety of experimental investigations.


Clinical pharmacology of carvedilol.

Animal work has shown that carvedilol is a nonselective beta-blocking drug. It has a vasodilator action from alpha-receptor blockade, but there is evidence that it has further action to relax smooth muscle, possibly from calcium channel antagonism. Carvedilol is lipid soluble and 25% bioavailable, and it has a half-life of about 7 h. It lowers blood pressure at rest and reduces the tachycardia and the rise of blood pressure on exercise. It reduces the level of blood pressure reached during isometric exercise or the cold pressor test. Cardiac output at rest is maintained, and the haemodynamics in the compromised heart is improved. It has an important peripheral vasodilator action, peripheral flow being maintained to important organs, e.g. kidneys, despite the fall in blood pressure. Exercising renin and noradrenaline levels are increased, as are the latter at rest. Carvedilol is lipid neutral. Carvedilol shifts the dose-response curve to isoprenaline to the right, as well as to alpha-stimulants such as phenylephrine. Responses to angiotensin are little affected. The ratio of beta- to alpha-blockade has been found to be 7.6 for 50 mg and 12.5 for 100 mg of carvedilol. There is no evidence of a decline in alpha-blockade after 1 week of continuous administration.


Antihypertensive effect of carvedilol: a preliminary dose-response study.

The blood pressure (BP) lowering effect of low doses of antihypertensive agents is not usually explored because of the difficulty in detecting small changes in BP. Since ambulatory blood pressure monitoring in a cross-over trial design can reliably detect differences of 5 mmHg with less than 20 subjects, we have used this technique to assess the dose-response curve of a new beta-blocker, carvedilol. Twenty subjects were enrolled after diagnostic ambulatory BP monitoring had shown a day-time average diastolic BP of over 90 mmHg. Three doses of carvedilol (6.25, 12.5 and 25 mg daily) and placebo were then given double-blind in random order for periods of 4 weeks each. No period effects were detected. The antihypertensive effect was statistically significant at doses of 12.5 mg and 25 mg daily. There was, however, no evidence that 25 mg/day produced the peak effect. The lowest dose (6.25 mg/day) produced a small fall in both systolic and diastolic BP but neither of these were significant. We conclude that doses of 12.5 and 25 mg carvedilol once a day are adequate for the treatment of hypertension.


Clinical experience with dual-acting drugs in hypertension.

There are now several antihypertensive agents with dual actions. Among these, labetalol has been studied most extensively. The drug has a place in the chronic treatment of hypertension and in the therapy of hypertensive emergencies. Carvedilol, now available in Germany, has been shown to be effective in different forms of hypertension. Celiprolol binds to beta 1- and beta 2-receptors. This drug also binds to alpha 2-receptors. It is not clear, at present, whether or not this binding property contributes to its antihypertensive effect.


Antihypertensive profile of carvedilol.

The spectrum of demands on an antihypertensive agent is constantly increasing. It is not only supposed to reduce blood pressure, but also to have a certain profile with regard to pathophysiology, hemodynamics, pharmacokinetics, safety, and clinical applicability. Carvedilol is a new beta-blocking agent without ISA, which causes vasodilation primarily through an alpha 1-blockade. It combines the positive effects of alpha 1- and beta-blockade; the negative properties are offset by each other. It not only provides theoretical advantages, but also shows a favourable hemodynamic profile and is effective and safe. Advantages in both primary and secondary prevention can be expected. It can be administered once daily, is well suited to patient needs, and can be combined with other hypertensive drugs. It also exerts a favorable influence on many secondary diseases. The compelling advantages of the drug make it an important addition to our armamentarium for the treatment of arterial hypertension as a first-line drug.


Comparison of the antihypertensive effects of carvedilol and metoprolol on resting and exercise blood pressure.

The present study was conducted to assess the efficacy and safety of carvedilol 50 mg as compared to metoprolol 200 mg at rest and during and after a standardized bicycle ergometric exercise test. Carvedilol is a novel non-selective beta-blocker without intrinsic sympathomimetic activity possessing vasodilatory properties primarily due to an alpha 1-antagonism in the same dose range. Both drugs were effective in reducing systolic and diastolic blood pressure at rest and during and after exercise. The reduction of diastolic blood pressure was much stronger under carvedilol treatment than under metoprolol treatment at all measurement points. Carvedilol was even effective in the treatment of patients whose blood pressure was unsatisfactorily controlled by metoprolol. This shows the importance of the vasodilation component of carvedilol. No serious adverse events were observed. Carvedilol therefore promises very well as a powerful and safe drug for the treatment of essential arterial hypertension.


Long-term hemodynamic effects of antihypertensive treatment.

The cardinal hemodynamic disorder in established essential hypertension is increased total peripheral resistance. During exercise, the increase in stroke volume of the heart is abnormal. A 20-year follow-up study of the hemodynamics in essential hypertension demonstrated a progressive increase in total peripheral resistance and deterioration of the heart pump function. Long-term treatment with antihypertensive agents modifies the circulatory system in different ways. Vasodilators (angiotensin converting enzyme inhibitors, alpha 1-blockers, and calcium antagonists) all reduce total peripheral resistance, and in general, cardiac output, heart rate, and stroke volume remain unchanged. Calcium antagonists like verapamil and diltiazem reduce the heart rate approximately 10% during exercise, but since stroke volume increases, cardiac output is unchanged. Chronic treatment with conventional beta-blockers induces a permanent reduction in cardiac output and heart rate during exercise. In contrast, carvedilol--a beta 1,beta 2-blocker with alpha 1-blocking activity--prevents the immediate increase in total peripheral resistance during acute beta-blockade. In 19 patients followed by hemodynamic measurements over 6-9 months, blood pressure was well controlled by carvedilol. During exercise, total peripheral resistance decreased 6% (P less than 0.05), and the reductions in heart rate and cardiac index were less than on conventional beta-blockade. Echo-Doppler studies showed a significant reduction in the intraventricular septum of 13%.


Hemodynamic and metabolic effects of carvedilol: a meta-analysis approach.

Establishing the overall efficacy or safety of a drug requires a unified methodological approach and analysis of all clinical trials to be included. As an example, this paper presents the aggregated dose-response relationship of efficacy data and a last-value analysis of laboratory data across all studies of the antihypertensive drug project carvedilol. Hemodynamic endpoints were calculated as change from the baseline blood pressure and pulse after an average treatment of 2-4 weeks whereas metabolic endpoints were calculated as changes from the baseline until the last day with respect to glucose, potassium, creatinine, lipids and liver function (median duration of treatment was 8-12 weeks). All antihypertensive trials were reanalyzed using an intent-to-treat principle. Aggregated efficacy data (mean, standard deviation, sample size) for each allocated group within each study were combined by means of meta-analysis separately for o.d. or b.i.d. dose regimens. Laboratory data were aggregated similarly within each study, using the last active drug as a grouping factor. The results showed that the patient population was treated adequately with 25 mg carvedilol o.d. The dose response curve for o.d. regimens shows a typical sigmoid shape: a steeper increase from 12.5 mg to 25 mg carvedilol, which then flattens (25 mg, 50 mg, 100 mg carvedilol o.d.). No superiority of a b.i.d. dose regimen over a o.d. dose regimen by means of BP lowering could be detected. There was a considerable variation in the results between studies, much bigger than the dose-response effect, most due to monocentric trials.(ABSTRACT TRUNCATED AT 250 WORDS)


The role of alpha- and beta-adrenoceptor blockade in antihypertensive treatment.

The alpha and beta-adrenoceptors are at present subdivided into alpha 1/alpha 2 and beta 1/beta 2 (probably also beta 3) subtypes. This subdivision, based on functional pharmacological studies, has been largely confirmed by molecular biological techniques. At presynaptic sites alpha 2- and beta 2-adrenoceptors are known to predominate, whereas both alpha 1/alpha 2- and beta 1/beta 2-receptors may be found at postsynaptic sites. This subdivision and classification of adrenoceptors, receptor changes in disease, and the availability of agonists and antagonists for the various receptor subtypes are discussed as the basis for antihypertensive drug therapy. alpha-Adrenoceptor antagonists are vasodilators, which owe their antihypertensive activity to arterial vasodilatation, while venous dilatation occurs simultaneously. Selective alpha 1-antagonists (prazosin, doxazosin) are preferable to the older nonselective compounds like phentolamine. beta-Blockers are useful antihypertensive agents used on a very large scale, but their mode of action remains unknown in detail. The combination of alpha- and beta-adrenoceptor blockade would be attractive, particularly for hemodynamic reasons. alpha-Adrenoceptor blockade reduces peripheral vascular resistance but also counteracts the vasoconstrictor effect of beta-blockers in the extremities, underlying the well-known side-effect of cold hands and feet. beta-Adrenoceptor blockade will not only contribute to the hypotensive effect but also suppress reflex tachycardia induced by alpha-adrenoceptor blockade.


Pathophysiology and triggers of acute myocardial infarction: clinical implications.

A new approach to identification of the triggering mechanisms of acute myocardial infarction has been provided by the observation that the disease occurs more frequently during the morning hours compared to other times of day. This circadian variation results primarily from an increased relative risk during the initial 2-3 h after awakening and arising. The precise relationship between the onset of myocardial infarction and external factors such as activity and meal patterns needs to be determined in controlled epidemiologic studies. The possible underlying pathophysiologic mechanisms responsible for the circadian pattern of myocardial infarction include acute variations of blood pressure, heart rate, platelet aggregability and fibrinolytic activity, leading to an increased risk of plaque rupture and intracoronary thrombosis. Clinical implications of these findings include the need to design preventive regimens to provide maximum protection at the time of peak risk of myocardial infarction.


Left ventricular hypertrophy regression during antihypertensive treatment.

For more than 20 years hypertrophy regression has been in the focus of hypertension research. Many studies in animals have shown impressive reduction of left ventricular hypertrophy after medical treatment of hypertension. The most important result seems to be that hypertrophy can be almost completely reversed in young animals, whereas in older animals regression of left ventricular hypertrophy appears to be less complete. Hypertrophy regression in man seems much more difficult to prove. The direct correlation between left ventricular muscle mass and ECG changes has been disappointing in many studies. Echocardiography is able to show a comparatively good impression of left ventricular muscle mass and therefore can also demonstrate regression of left ventricular hypertrophy within its methodological limits. There is no doubt that today magnetic resonance imaging has by far the best imaging quality of all the clinical methods and is able to demonstrate both hypertrophy and its regression with incomparable accuracy. In the present clinical study hypertrophy regression has been demonstrated after 6 months of treatment with Carvedilol.


Acute hemodynamic effects of carvedilol in comparison with propranolol in patients with coronary heart disease.

In a randomized, double-blind study oral doses of 50 mg carvedilol (Dilatrend) were compared with 40 mg propranolol in 16 male patients with coronary heart disease, CHD [12 without significant stenoses following percutaneous transluminal coronary angioplasty (PTCA), 4 with multivessel disease]. Bicycle ergometry in the supine position was performed before and 80 min after drug application; measurements were done at rest, during and after exercise. Clinically, the total exercise time and the onset of angina and exhaustion were noted, while the investigated hemodynamic parameters were heart rate, systemic and pulmonary pressures and resistances, cardiac index, and lower limb blood flow. Clinically, carvedilol improved the exercise tolerance more than propranolol as regards angina and exhaustion. Hemodynamically, carvedilol did not lead, as the classic betablocker propranolol does, to an increase in systemic or pulmonary resistance, to a decrease in cardiac output, or to an increase of the pulmonary capillary wedge pressure during exercise, but instead caused opposite changes. In contrast to propranolol, the post exercise lower limb blood flow had increased significantly. The differences in action between the two betablockers can be explained by the vasodilating properties of carvedilol. Due to these acute effects, carvedilol may be preferred to propranolol in the treatment of CHD patients with hypertension, peripheral occlusive artery disease, and/or coronary vasospasm.


Can intravenous beta blockade predict long-term haemodynamic benefit in chronic congestive heart failure secondary to ischaemic heart disease? A comparison between intravenous and oral carvedilol.

Several studies in the past have shown the long-term beneficial effects of beta-blockers in congestive heart failure. Despite the interest in this mode of therapy, their clinical application has been limited due to their negative inotropic effect. A subset of the heart failure patients do not show any improvements with standard beta-blocker therapy. Carvedilol, a new, non-selective beta-blocking agent with concurrent alpha-blocking properties, was evaluated in 17 patients with chronic heart failure secondary to ischaemic heart disease. All had resting left ventricular ejection fraction less than or equal to 45% and were maintained on diuretic therapy. Acute haemodynamic measurements were made after intravenous carvedilol (2.5-7.5 mg) and also after chronic therapy for 8 weeks (carvedilol 12.5-50 mg b.d.). Radionuclide ventriculography, ambulatory intra-arterial blood pressure monitoring and right heart catheterization were performed before and after 8 weeks of chronic therapy. Twelve patients completed the study and 5 were withdrawn. Symptomatic and haemodynamic improvement was demonstrated in 11 of the 12 patients after 8 weeks of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)


Effect of psychotropic drugs on excitatory amino acids in patients undergoing psychosurgery for depression.

Samples of ventricular CSF were taken from 52 consecutive patients admitted for psychosurgery for intractable depression. Concentrations of asparagine, aspartate, glutamine, glutamic acid, and serine were determined. Glutamate and aspartate concentrations, implicated in excitotoxic brain damage, were not affected by various types of psychotropic drug treatment. Serine, a modulator of glutamate responses, was significantly elevated in samples from subjects receiving antidepressants. These subjects responded poorly to the operation. Psychotropic drugs are unlikely to be neurotoxic. Nevertheless, antidepressants may influence excitatory neurotransmission.


The effect of neuroleptics on cognitive and psychomotor function. A preliminary study in healthy volunteers.

The effects of haloperidol (1 mg), benzhexol (5 mg), diazepam (10 mg) and caffeine (400 mg) on subjective and objective measures of cognitive and psychomotor function were compared with placebo in 20 healthy volunteers. While both diazepam and benzhexol were associated with highly significant impairments in subjective altertness, critical flicker fusion threshold and choice reaction time (CRT), haloperidol could not be distinguished from placebo in most tests but was actually associated with an apparent improvement in CRT (in males) and simple visual reaction time. The perceptual maze test detected impairment by benzhexol on processing speed but was not sensitive to any other drug effects. Multiple-dose studies are required to establish if there is a true activating effect of haloperidol using a test of sustained attention. No effect of Eysenck personality subtype or life events on baseline or drug response data was detected.


Dissociation of serotoninergic and dopaminergic components in acute effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in mice.

Behavioural and neurochemical effects of acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment in mice have been studied in order to determine the change in the neurotransmitter profile of the following areas of the brain: substantia nigra (SN), nucleus caudatus putamen (NCP), limbic system (LS; tuberculum olfactorium and nucleus accumbens), medulla oblongata (MO) and cerebellum (CER). Subcutaneous administration of MPTP (40 mg/kg) caused behavioural syndromes including restlessness, straub tail, hindlimb abduction, tremor, jumping, bradykinesia and akinesia in Balb/c mice. There existed a well-defined biphasic profile of motor activity comprising of an initial excitatory phase followed by an inhibitory phase lasting about two and a half and five hours, respectively. A significant rise in 5-hydroxytryptamine (5-HT) content together with a decreased 5-HT utilization as evidenced by lower 5-hydroxyindole acetic acid (5-HIAA) to 5-HT ratio in the above brain areas demarcated the excitatory phase, whereas the inhibitory phase was distinguished by a significant decrease in dopamine (DA) content along with an increased turnover of the amine as shown by a higher homovanillic acid (HVA) to DA ratio in the functionally important nuclei of the extrapyramidal system like SN, NCP and LS. Methysergide, a nonspecific 5-HT receptor blocker, but not ketanserin, a specific 5-HT2 antagonist, prevented the occurrence of the initial excitatory phase without affecting the depressive phase. Administration of apomorphine, a dopamine agonist, 30 minutes prior to MPTP was ineffective, whereas its application 90 minutes after MPTP prevented the occurrence of bradykinesia and akinesia. Interestingly, treatment with haloperidol, the dopamine (D1/D2) antagonist, before and after MPTP administration caused an early onset and prolongation of the inhibitory phase without affecting the initial hyperexcitement. The results provide direct evidence for the involvement of serotoninergic and dopaminergic mechanisms in the genesis of the early and late syndromes of acute MPTP poisoning respectively.


Synaptic potentials and effects of amino acid antagonists in the auditory cortex.

Neurons of in vitro guinea pig and rat auditory cortex receive a complex synaptic pattern of afferent information. As many as four synaptic responses to a single-stimulus pulse to the gray or white matter can occur; an early-EPSP followed, sequentially, by an early-IPSP, late-EPSP, and late-IPSP. Paired pulse stimulation and pharmacological studies show that the early-IPSP can modify information transmission that occurs by way of the early-EPSP. Each of these four synaptic responses differed in estimated reversal potential, and each was differentially sensitive to antagonism by pharmacological agents. DNQX (6,7-dinitroquinoxaline-2,3-dione), a quisqualate/kainate receptor antagonist, blocked the early-EPSP, and the late-EPSP was blocked by the NMDA receptor antagonist APV (D-2-amino-5-phosphonovalerate). The early-IPSP was blocked by the GABA-a receptor antagonist bicuculline, and the late-IPSP by the GABA-b receptor antagonists 2-OH saclofen or phaclofen. Presentation of stimulus trains, even at relatively low intensities, could produce a long-lasting APV-sensitive membrane depolarization. Also discussed is the possible role of these synaptic potentials in auditory cortical function and plasticity.


Norepinephrine increases angiotensin II binding in rat brain synaptosomes.

Synaptosomes prepared from rat hypothalamus or brainstem contain specific binding sites for [125I]-angiotensin II (AII). Treatment of these synaptosomes with norepinephrine (NE) (10-500 microM) for 60 min results in a concentration-dependent increase in [125I]-AII specific binding which appears to be an increase in the number rather than the affinity of these binding sites. This effect of NE is qualitatively similar in synaptosomes prepared from neonate (one-day-old) or adult (140-day-old) rats. Furthermore, it is antagonized by prazosin (10 microM) but not by yohimbine (10 microM), indicating the involvement of alpha 1-adrenergic receptors. Finally, this effect of NE may involve activation of protein kinase C (PKC) because it is mimicked by a PKC agonist (TPA, 0.8 microM; 60 min) and is blocked by a PKC antagonist (H-7, 100 microM). These results match our previous findings on the regulation of AII receptors in neurons cultured from the hypothalamus and brainstem of neonate rats and provide strong evidence for a role of this catecholamine in the modulation of brain AII receptors.


Ethanol inhibits epileptiform activity and NMDA receptor-mediated synaptic transmission in rat amygdaloid slices.

The effect of ethanol on the epileptiform activity induced by Mg(++)-free solution was studied in rat amygdalar slices using intracellular recording techniques. The spontaneous and evoked epileptiform discharges consisting of an initial burst followed by afterdischarges were observed 20-30 min after switching to Mg(++)-free medium. Superfusion with ethanol (20-100 mM) reversibly reduced the duration of spontaneous and evoked bursting discharges in a concentration-dependent manner. Synaptic response mediated by N-methyl-D-aspartate (NMDA) receptor activation was isolated by application of a solution containing the non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and either in Mg(++)-free solution or in the presence of 50 microM bicuculline. Application of ethanol reversibly suppressed the duration of NMDA receptor-mediated synaptic response. These results suggest that intoxicating concentrations of ethanol possess anticonvulsant activity through blocking the NMDA receptor-mediated synaptic excitation. In addition, the observed effect of ethanol on NMDA receptor-mediated synaptic response could be relevant to the cognitive and behavioral manifestations seen in some alcoholics.


Subtypes of substantia nigra dopaminergic neurons revealed by apamin: autoradiographic and electrophysiological studies.

In the intact animal, some substantia nigra dopaminergic neurons exhibit regular, and some exhibit burst firing patterns. In the in vitro slice preparation, however, all dopaminergic neurons exhibit a nonburst firing pattern. Burst firing patterns are thought to be regulated, in part, by a small conductance calcium-activated potassium channel (SK channels). To test whether SK channels reside within the midbrain dopaminergic cell regions of the mouse, receptor autoradiographic experiments were conducted with the SK channel antagonist, 125I-apamin. To determine whether SK channels play a role in burst firing pattern generation in substantia nigra dopaminergic neurons, changes in firing patterns of these cells were examined in the in vitro slice preparation following apamin superfusion (1-1000 nM). It was demonstrated that a) specific binding of radiolabeled apamin was found within the dopaminergic cell regions of the substantia nigra pars compacta, and ventral tegmental area (2.7-4.7 fmol/mg tissue); b) the firing patterns of less than half of the dopaminergic neurons were changed from a regular pattern to that of a burster with concentrations as low as 1 nM, but the firing patterns of many neurons were not changed by the drug; and c) blockade of the SK channel did not interfere with the inhibitory effects of dopamine on dopaminergic neuronal impulse flow, indicating that the known hyperpolarizing effects mediated by this dopamine receptor are not importantly mediated via the SK channel.


Benzodiazepine reversal with flumazenil--a review of the literature.

Benzodiazepines such as Valium (diazepam) or Versed (midazolam), as used in dental procedures for intravenous sedation, have been a boon to the profession. Yet in the event of sedation problems, no agent exists that consistently reverses all clinical effects of these drugs. This problem does not exist with narcotics, frequently employed in tandem with benzodiazepines, since an effective reversal agent, Narcan (naloxone hydrochloride), exists. It would be advantageous to effectively reverse benzodiazepines in cases of acute emergency with respiratory depression or paradoxical reactions, and to allow quick, full recovery after short dental procedures. None of the drugs currently available for benzodiazepine reversal, such as physostigmine, give consistent clinical results. The purpose of this paper is to discuss Flumazenil, a new specific benzodiazepine receptor antagonist, and its possible use for dental sedation procedures.


The pharmacoepidemiology of treatment-refractory schizophrenia.

Treatment-refractory schizophrenia is a major clinical problem for which there is relatively little scientific information, and no consensus has been reached on approaches to treatment. The pharmacotherapy used for 103 patients with a diagnosis of schizophrenia or schizoaffective disorder at one psychiatric hospital was examined. Data were gathered on neuroleptic choice and dose, the use of adjunctive treatments and serum neuroleptic levels. The daily neuroleptic dose was compared with that of random samples of patients receiving outpatient maintenance treatment, and short-stay patients receiving acute treatment. The patients in our sample received high doses of neuroleptics despite a persistent lack of response to treatment, and despite the fact that these were in excess of the recommended maximum beneficial dose. The appropriateness of this therapy is discussed.


Can drug-induced depressions be identified by their clinical features?

Drug-induced depression is classified by the DSM-III-R as an organic mood syndrome of the depressed type. Because drugs have specific pharmacological effects and mechanisms of action, depressive syndromes induced by specific drugs may have characteristic clinical features. An awareness of such features would be valuable for clinical purposes. This review is an attempt to summarize the information on clinical features of drug-induced depressions. The review determined that no unique clinical features have been identified for depressive syndromes associated with most drugs. However, the literature did suggest that depressions associated with oral contraceptive agents may differ significantly from non organic major depressive episodes.


C-erbB-2 oncoprotein expression versus internal mammary lymph node metastases as additional prognostic factors in patients with axillary lymph node-positive breast cancer.

The relationship was assessed between c-erbB-2 oncoprotein expression and other prognostic factors in breast cancer, such as axillary and internal mammary node metastases. The value of these indicators was analyzed in estimating prognosis, especially in patients with axillary node-positive breast cancer. These results showed that c-erbB-2 is significantly related to clinical stage and axillary node metastases. A univariate study revealed that disease-free and overall survival were correlated significantly with clinical stage, tumor size, axillary and internal mammary node metastases, and 21N status. Among the patients with axillary node involvement, however, 21N status did not appear to be a significant additional prognostic factor. Internal mammary node metastases were significant. In a multivariate study, only axillary and internal mammary node metastases were significant prognostic factors for either the entire group of patients or those with positive axillary nodes. Therefore, axillary node dissection and biopsy of the internal mammary nodes may provide important prognostic information for patients with breast cancer.


Cowden's disease. A case report with analyses at the molecular level.

Cowden's disease (multiple hamartoma syndrome) is characterized by multiple hamartomas of ectodermal, endodermal, and mesodermal origin, a high incidence of malignant tumors of the breast and/or thyroid gland, and an autosomal dominant pattern of inheritance. Similar to sporadic breast cancer, chromosomal studies have not elucidated the cause of this syndrome. The authors report the case of a patient with this syndrome and analyze the pattern of amplification or rearrangement of three genes: the HER-2/neu oncogene, the ras oncogene, and the estrogen-inducible gene, pS-2. All three of these genes were present in single copies without translocations. It was noteworthy that three of the most important genes currently studied in relation to breast cancer existed in a unamplified unrearranged state in this patient. Those with clinical manifestations of Cowden's disease may be candidates for prophylactic bilateral total mastectomy, and the authors recommend that these patients undergo this procedure by their third decade of life. An alternative to this approach would entail monthly self examinations, breast examinations by the patient's physician every 3 months, bilateral mammograms every 6 to 12 months, and biopsy of any suspicious lesions. It is crucial, however, that these patients be identified by their mucocutaneous lesions and family history before an underlying malignant lesion develops.


Multiple drug resistance gene expression in human renal cell cancer is associated with the histologic subtype.

Overexpression of p170 glycoprotein, the product of the multiple drug resistance (mdr) gene, has been associated with resistance to various cytotoxic drugs used in the treatment of human neoplasms. Normal renal epithelial cells express p170 as a function of their secretory capacity. Because renal cell carcinomas (RCC) respond poorly to chemotherapeutic regimens, p170 expression was studied in primary RCC. Such expression was measured in 40 human RCC and normal kidney tissues using immunohistochemical staining with the monoclonal antibody C-219. Staining intensities of the whole tumor and of different areas of the cryostat sections were transformed into digital numbers using an algorithm designed for this purpose. In most tumors, an inhomogeneous staining pattern and a correlation between grade of differentiation and C-219 immunoreactivity was observed. A comparison of the tumors according to their histopathologic subtypes showed clear differences. The means (range) of the staining intensities of the different types of RCC: clear cell carcinoma Grade 1 (n = 3), 2.0 (2.0 to 2.0); clear cell carcinoma Grade 2 (n = 19), 0.8 (0.0 to 2.9); clear cell carcinoma Grade 3 (n = 5), 0.1 (0.0 to 0.2); tubular carcinoma (n = 4), 2.0 (2.0 to 3.0); anaplastic carcinoma (n = 8), 0.05 (0.0 to 0.2); oncocytoma (n = 1), 0.0 (0.0 to 0.0); and normal kidney (n = 40), 0.5 (0.0 to 2.0). The differences between anaplastic, clear cell, and tubular carcinoma were significant (P less than 0.001 by Kruskal-Wallis test). In addition, the difference between the three subgroups of clear cell carcinoma was significant (P less than 0.01). It was concluded that the histopathologic subtypes of RCC correlate with the degree of mdr gene expression, as determined by staining with the C-219 monoclonal antibody.


Multidrug-resistant phenotype of disease-oriented panels of human tumor cell lines used for anticancer drug screening.

Disease-oriented panels of human tumor cell lines used by the National Cancer Institute for large-scale in vitro anticancer drug screening were evaluated for multidrug-resistant phenotype at the functional (in vitro drug sensitivity) and molecular levels. The cell line panels manifested a broad range of sensitivities to drugs typically associated with multidrug resistance (MDR) as well as to drugs not associated with MDR. Individual cell lines displayed unique and characteristic profiles of response. Patterns of correlated response were observed among, but not between, MDR and non-MDR drugs. Strong evidence of correlated response was limited to drugs sharing an intracellular mechanism of action. Several tumor cell lines exhibited a high degree of resistance to MDR drugs and relative sensitivity to non-MDR drugs, contained high levels of MDR-1 mRNA, and expressed cell surface P-glycoprotein detectable with one or more monoclonal antibodies. Parallel expression of all of these features representing the classic MDR phenotype was observed among members of the colon and renal tumor panels. Certain individual cell lines among other panels (lung, ovarian, melanoma, and central nervous system) also manifested some aspects of the MDR phenotype to various extents. Identification of MDR cell lines used for large-scale in vitro anticancer drug screening will facilitate interpretation of data in a way which may allow identification of new drug leads of potential value in treatment of MDR tumor cell populations.


Increased expression of human ribosomal phosphoprotein P0 messenger RNA in hepatocellular carcinoma and colon carcinoma.

To search for differentially expressed gene products in selected cancers of endodermal origin, cDNA libraries derived from mRNA in human hepatocellular carcinoma and adjacent grossly normal tissue were generated. From these parent libraries, subtracted cDNA libraries of tumor minus normal and normal minus tumor tissues were constructed. After screening these subtracted libraries by +/- hybridization, a cDNA clone that is overexpressed in hepatocellular carcinoma and encodes the human acidic ribosomal phosphoprotein P0 (P0) was identified. We then evaluated the expression of this phosphoprotein P0 in human colon carcinoma samples. Surgical specimens of primary tumors and liver metastases were examined by Northern hybridization of total RNA with one of 2 32P-labeled P0 probes. The mRNA level of the P0 was greater in primary colon carcinoma than in paired adjacent normal colonic epithelium in 36 of 38 cases; the mean tumor/normal ratio was 2.7 (range, up to 13). The tumor/normal ratio, when plotted against the Dukes' stage of disease, gave evidence for increasing P0 expression with increasing stage of colon carcinoma (P = 0.02). In all 8 cases of paired colon carcinoma metastatic to liver and 2 cases of paired primary hepatocellular carcinoma, the P0 mRNA level was greater in tumor than in adjacent normal liver tissue. The mean tumor/normal ratio was 4.0 (range, up to 11) for the colon cancers metastatic to liver and 4.2 for the primary hepatocellular carcinoma samples. These findings support a common increased expression of selected gene products in different tumors of endodermal origin and suggest that increased P0 expression, in line with certain other ribosomal proteins, may be associated with human colorectal cancer progression and biological aggressiveness.


Sialyl Lewis(x) antigen as defined by monoclonal antibody AM-3 is a marker of dysplasia in the colonic adenoma-carcinoma sequence.

Monoclonal antibody AM-3 (MAb AM-3) raised against a sialomucin from human colorectal carcinoma has previously been shown to define a carbohydrate epitope, which is detectable by immunocytochemistry on all investigated colonic carcinomas and is expressed in correlation with the grade of dysplasia in colonic adenomas (Hanski et al., J. Clin. Pathol., 43: 379-385, 1990). Epitope analyses in solid-phase enzyme immunoassays revealed that AM-3 antibody recognizes the sialylated Lewis(x) sequence on a branched O-linked glycan and its reductively cleaved alditol from human amniotic mucins. In comparative binding and binding inhibition studies MAbs AM-3 and CSLEX1 displayed reciprocal affinities to mucins versus gangliosides. Correspondingly, the weaker binding activities of AM-3 versus CSLEX to III3-alpha Fuc-IV3-alpha NeuAc-nLcOse4-Cer or to monogangliosides from human granulocytes were measured. Gangliosides from a human colon carcinoma were recognized by MAb CSLEX1 exhibiting a broader specificity to various sialyl-Lewis(x) antigens and by MAb FH6 reactive to sialyl-dimeric Lewis(x) antigen, but not by MAb AM-3. In conclusion, MAb AM-3 is distinguished from other sialyl Lewis(x)-specific MAbs by its selective reactivity to mucin-carried epitopes on the monomeric antigen.


Acquisition of a tumorigenic phenotype by a rat ventral prostate epithelial cell line expressing a transfected activated neu oncogene.

The neu oncogene has been demonstrated to be a potent transforming gene in rodent fibroblasts. The overexpression of the human erbB-2/neu oncogene has been implicated in the development and/or prognosis of several human carcinomas including that of the prostate. To assess the transforming potential of the activated rat neu oncogene in prostatic epithelial carcinogenesis, this laboratory has transfected a cloned non-tumorigenic, rat ventral prostate epithelial cell line, NbE-1.4, with an activated, point-mutated neu oncogene. Transfection of NbE-1.4 cells with the activated neu oncogene expression vector, pSV-neu-T (neu-T), resulted in an altered cell morphology, an increase in soft agar colony-forming efficiency, and conversion to a tumorigenic phenotype. Although the parental NbE-1.4 cells expressed endogenous c-neu mRNA, a reverse transcriptase polymerase chain reaction assay determined that the neu-T-transfected clones expressed only the point-mutated neu-T mRNA. The suppression of the c-neu transcripts occurred regardless of the neu-T mRNA level expressed in these cell clones. These data provide evidence to show that low-level expression of an activated neu oncogene alone was insufficient to transform rat prostate epithelial cells. Rather, overexpression of an activated neu oncogene correlated well with the acquisition of a tumorigenic phenotype by the NbE-1.4 epithelial cell line.


Ganglioside, adhesion molecule, and HLA antigen expression in basal cell carcinoma lesions.

The antigenic profile of basal cell carcinoma (BCC) cells was analyzed by immunoperoxidase staining of 27 surgically removed BCC lesions with antiganglioside, antiadhesion molecule, and antihistocompatibility locus antigen (HLA) monoclonal antibodies (MoAb). The large majority of BCC lesions were stained by antiganglioside MoAb; among the latter the anti-GD3 ganglioside MoAb R24 displayed the broadest reactivity. The GD3 ganglioside expression by BCC cells, which was corroborated by thin layer chromatography immunostaining with MoAb R24, appears to be a proliferation dependent phenomenon. Among the adhesion molecules tested vitronectin receptor and CDw44 were found in up to 70% of the lesions tested, while intercellular adhesion molecule 1 (ICAM-1) was detected in only a low percentage of BCC cells in one lesion. ICAM-1 was not induced on BCC cells in five and three lesions removed 24 and 48 h, respectively, following the intralesional injection of gamma-interferon. The latter enhanced HLA Class I antigen expression and induced ICAM-1 expression by the surrounding keratinocytes; furthermore gamma-interferon induced HLA Class II antigen expression by a small percentage of BCC cells in three lesions. These results suggest that malignant transformation of keratinocytes is associated with a selective loss of susceptibility to induction by cytokines of ICAM-1 expression. Besides confirming the low HLA Class I and Class II antigen expression by BCC cells, the present investigation has shown a differential expression of distinct monomorphic determinants of HLA Class I antigens and a lower expression of HLA-A antigens than of HLA-B antigens by BCC cells. Furthermore, the present study has shown that HLA Class II antigens can be induced on BCC cells by cytokines.


Effect of a low-tryptophan diet as an adjuvant to conventional neuroleptic therapy in schizophrenia.

Eleven patients with DSM-III-R schizophrenia were entered into a 4-day tryptophan (TRP)-deficient diet. The diet lowered total plasma TRP levels in all patients; during the diet phase, there was a greater than 50% reduction in mean total plasma TRP levels from the pre-diet phase. The low-TRP diet improved performance on the Stroop Color and Word Test. These data are especially intriguing in view of the suggestion that a deficit in color-word naming is related to frontal lobe dysfunction and the possible occurrence of frontal lobe abnormalities in patients with schizophrenia. Interestingly, depressive symptomatology did not emerge on the TRP-deficient diet, despite the lowering of total plasma TRP levels. There were statistically significant improvements noted on objective ratings of the severity of psychotic symptomatology; however, these statistical improvements were without obvious clinical significance, as the magnitude of the changes on the behavioral ratings were minimal. The results of this study suggest that there might be some adjuvant potential for a low-TRP diet in the treatment of schizophrenia, and that schizophrenia or antipsychotic medications might offer some protection against the depressive effects of a TRP-deficient diet.


Glutamatergic therapy of Huntington's chorea.

Preclinical evidence suggests that hypofunction of the glutamatergic subthalamopallidal tract may contribute to the hyperkinesis in Huntington's chorea. The clinical effects of milacemide, a glycine prodrug, were studied in seven patients with Huntington's disease under double-blind, placebo-controlled conditions. Oral doses of 1,200 mg/day did not alter chorea or cognitive dysfunction. Specific modulatory effects of glycine on the NMDA subtype of glutamate receptors, rather than the AMPA receptors, which may predominate among target neurons of the subthalamus, may explain the therapeutic failure of milacemide.


Cytochromes c1 and b2 are sorted to the intermembrane space of yeast mitochondria by a stop-transfer mechanism.

The pathway by which cytochromes c1 and b2 reach the mitochondrial intermembrane space has been controversial. According to the "conservative sorting" hypothesis, these proteins are first imported across both outer and inner membranes into the matrix, and then are retranslocated across the inner membrane. Our data argue against this model: import intermediates of cytochromes c1 and b2 were found only outside the inner membrane; maturation of these proteins was independent of the matrix-localized hsp60 chaperone; and dihydrofolate reductase linked to the presequence of either cytochrome was imported to the intermembrane space in the absence of ATP. We conclude that cytochromes c1 and b2 are sorted by a mechanism in which translocation through the inner membrane is arrested by a "stop-transfer" signal in the presequence. The arrested intermediates may be associated with a proteinaceous channel in the inner membrane.


LEAFY controls floral meristem identity in Arabidopsis.

The first step in flower development is the generation of a floral meristem by the inflorescence meristem. We have analyzed how this process is affected by mutant alleles of the Arabidopsis gene LEAFY. We show that LEAFY interacts with another floral control gene, APETALA1, to promote the transition from inflorescence to floral meristem. We have cloned the LEAFY gene, and, consistent with the mutant phenotype, we find that LEAFY RNA is expressed strongly in young flower primordia. LEAFY expression procedes expression of the homeotic genes AGAMOUS and APETALA3, which specify organ identify within the flower. Furthermore, we demonstrate that LEAFY is the Arabidopsis homolog of the FLORICAULA gene, which controls floral meristem identity in the distantly related species Antirrhinum majus.


Substance abuse.

The three types of drugs commonly used in sports--therapeutic drugs, performance-enhancing drugs, and recreational drugs--have been discussed and presented in a way that should be helpful to health care providers dealing with athletes. The goal of this article has been not only to present information concerning drugs but also to raise the awareness level so that abuse of all types of drugs will be considered by athletic trainers, physicians, and health care providers when they deal with athletes. The role of the physician in the area of drug abuse is no different than the physician's role in dealing with any health problem, diagnosis, and management. The responsibility of the physician who deals with athletes always has been, is, and always will be the health and safety of the athlete.


[Therapy of the adverse effects of neuroleptics].

The authors analyzed 65 women patients treated with neuroleptics and evaluated the results in accordance the SARS scale with regard to side-effects of the neuroleptic therapy. They dealt with the problem of convenience of treatment with antiparkinsonics to minimize side-effects of neuroleptics.


[Analysis of RFLP haplotypes in the beta-globin gene cluster and the identification of beta-thalassemia genes in patients from Guangdong Province].

RFLP haplotypes of 69 chromosomes from members of 18 families affected with beta-thalassemia (beta T) in Guangdong Province were analyzed. 17 haplotypes were found. Haplotypes 1, 2 and 3 accounted for most of them and 4 new haplotypes were identified, three of which were associated with beta T genes. In 9 families, the haplotype data could be used for definitive prenatal diagnosis. In 7 families, 50% exclusive diagnosis could be achieved. In order to know the frequencies of various beta T genes in Guangdong Province and to improve prenatal diagnosis, we identified the beta T genes of 46 affected children in Guangdong Province by amplifying beta-globin gene sequences with the polymerase chain reaction (PCR) and hybridization with allele specific oligonucleotide (ASO) probes. 82 beta T genes hybridized with 6 probes. The most common beta T mutations were frameshift 41/42-TCTT, -28 A----G and IVS-2 nt654 G----T, accounting for 80% of the total. In 36 families PCR combined with hybridization using 6 ASO probes could provide definitive prenatal diagnosis.


[Analysis of RFLP haplotypes and point mutations at the phenylalanine hydroxylase (PAH) locus in PKU families from north China].

A study of DNA polymorphisms at the phenylalanine hydroxylase (PAH) locus was performed using 28 classical phenylketonuria (PKU) families from North China. In the families analyzed, haplotype 4 accounted for 77% of normal chromosomes and 79% of PKU gene bearing chromosomes. Two new haplotypes, haplotypes 49 and 50, were found. On the basis of haplotype analysis, only 37%-40% of PKU carriers in North China were heterozygous and therefore informative for linkage studies. Exon 3 (Arg111----stop) and exon 6 (Tyr204----Cys204) mutations of the PAH gene were studied using the polymerase chain reaction (PCR) and allele specific oligonucleotide probe hybridization in 42 PKU families from North China. These accounted for 3.6% and 9.5% of PKU mutations in North China, respectively.


Linkage analysis and long QT syndrome. Using genetics to study cardiovascular disease.

Recombinant DNA technologies have facilitated the development of a set of polymorphic DNA markers covering the human genome. General linkage analysis in families predisposed to inherited disease is now feasible. Linkage analysis can help identify a disease gene even when relatively little is known about the disorder. Using this approach, we have identified linkage between a gene that causes the long QT syndrome and DNA markers on chromosome 11. The identification of the chromosomal location of the long QT locus is the first step in defining the specific mutations that cause this disease.


Are contraction and relaxation coupled in patients with and without congestive heart failure?

Although changes in contractility are often accompanied by changes in relaxation, a mathematical model of ventricular coupling has not been described. A model we examined suggests a hyperbolic relation between measurements of contraction and relaxation. We thus tested the hypothesis that relatively load-independent measurements of contractility (end-systolic elastance [Ees]) and relaxation (the slope of the tau-to-end-systolic pressure relation [R]) were coupled. To establish the validity of the model, an assessment of Ees and R was made in 30 subjects who underwent sequential digital ventriculography and micromanometer pressure measurements during atrial pacing (93 +/- 10 min-1) before and after graded doses of nitroprusside. To establish if a cyclic AMP (cAMP)-mediated intervention alters coupling, seven of the 30 subjects were studied before and after 3 months of beta-blockade. To determine if a non-cAMP-mediated intervention alters coupling, 12 other patients were studied before and after deslanoside. Nonlinear regression analysis for the initial 30 patients suggested a hyperbolic relation: (Ees) (R) = 1.05 (r = 0.79, p less than 0.001) with an inflection point near Ees = 1.02 mm Hg/ml. Thus, with normal or near-normal contractility, relaxation is normal and not load dependent (R is close to 0). With systolic dysfunction, relaxation becomes very afterload dependent and so must be normalized for load. After long-term beta-blockade in patients with severe left ventricular dysfunction, small improvements in contractility (elastance) occurred with larger changes in relaxation, but the curve describing the relation was not displaced. Acute administration of deslanoside resulted in a large increase in elastance and a smaller change in relaxation but did not alter coupling. However, the magnitude of the change in R was dependent on the predrug R value. These data suggest contraction and relaxation may be physiologically coupled with relaxation relatively preserved in early heart failure and more rapid deterioration in relaxation as elastance falls under 1.02 mm Hg/ml. Both beta-blockers (which may act through cAMP) and digitalis (which is cAMP independent) improve contraction and relaxation, but both mechanisms appear to maintain coupling. The hyperbolic relation between contraction and relaxation may have important implications regarding therapeutic response and selection of patients for clinical trials in heart failure.


Impact of dual-chamber permanent pacing in patients with obstructive hypertrophic cardiomyopathy with symptoms refractory to verapamil and beta-adrenergic blocker therapy.

Patients with obstructive hypertrophic cardiomyopathy (HCM) with symptoms refractory to drugs (beta-blockers or verapamil) are candidates for cardiac surgery (left ventricular septal myectomy or mitral valve replacement). The present study examines prospectively the ability of dual-chamber (DDD) pacing to improve symptoms and relieve left ventricular outflow obstruction in such patients. Forty-four consecutive patients with obstructive HCM who had failed to benefit from pharmacotherapy underwent treadmill exercise tests, echocardiography, and cardiac catheterization before and 1.5-3 months after implantation of a DDD pacemaker. Symptoms (angina, dyspnea, palpitations, presyncope, and syncope), New York Heart Association functional class status (1.7 +/- 0.7 versus 3.4 +/- 0.5, p less than 0.00001), and exercise durations were improved at follow-up evaluation. This was associated with significant reduction in left ventricular outflow tract gradient (38 +/- 38 versus 87 +/- 43 mm Hg, p less than 0.0001) and significant increases in cardiac output and systemic arterial pressures. Notably, when pacing was discontinued and comparisons were made in sinus rhythm, treadmill exercise durations were greater and left ventricular outflow tract gradients were less at the follow-up evaluation compared with the baseline study. DDD pacing is an effective alternative to surgery in most patients with obstructive HCM with drug-refractory symptoms. The beneficial effects of pacing continue to be evident when pacing is acutely discontinued.


Assay of gamma-glutamyltransferase with amino acid dehydrogenases from Bacillus stearothermophilus as auxiliary enzymes.

A spectrophotometric assay for serum gamma-glutamyltransferase (gamma-GT, EC 2.3.2.2) based on the increasing absorbance at 340 nm due to NADH formation is described. Using gamma-glutamyl dipeptides as the donor substrate, amino acids formed by the gamma-glutamyl transfer from the donor substrate to the acceptor substrate glycylglycine are stoichiometrically converted by the corresponding amino acid dehydrogenases from Bacillus stearothermophilus to produce their keto acids and NADH. gamma-Glutamylalanine was found to be the most specific and sensitive donor substrate. The method can be mechanized, is free of interference and correlates well with conventional methods.


Clonal heterogeneity of synovial fluid T lymphocytes in inflammatory synovitis.

Several studies have examined patients with rheumatoid arthritis for the presence of oligoclonal populations of synovial T lymphocytes. The results of these studies have been conflicting. In this study one patient with rheumatoid arthritis and two with other forms of inflammatory synovitis were examined by Southern blot analysis of T cell clones generated from synovial fluid by primary limiting dilution. Evidence of oligoclonality was documented only in a patient with psoriatic arthritis. The distinguishing characteristics of this patient, in addition to the diagnosis, included the fact that only one joint was involved, the synovitis in the affected joint was of recent onset, and the synovial fluid lymphocytes from which the T cells were cloned responded strongly to soluble antigens. Because of the association with the strong response to soluble antigens, synovial fluid T lymphocytes from another patient with rheumatoid arthritis were cloned in response to a crude mycobacterial antigenic mixture. Three of the seven clones examined were identical by Southern blot analysis. These observations suggest that the presence of oligoclonality is limited in patients with inflammatory arthritis. The relationship of a specific antigen-driven response within the joint to the detection of oligoclonal T cells within that joint remains to be determined.


Mechanism of anteroposterior axis specification in vertebrates. Lessons from the amphibians.

Interest in the problem of anteroposterior specification has quickened because of our near understanding of the mechanism in Drosophila and because of the homology of Antennapedia-like homeobox gene expression patterns in Drosophila and vertebrates. But vertebrates differ from Drosophila because of morphogenetic movements and interactions between tissue layers, both intimately associated with anteroposterior specification. The purpose of this article is to review classical findings and to enquire how far these have been confirmed, refuted or extended by modern work. The "pre-molecular" work suggests that there are several steps to the process: (i) Formation of anteroposterior pattern in mesoderm during gastrulation with posterior dominance. (ii) Regional specific induction of ectoderm to form neural plate. (iii) Reciprocal interactions from neural plate to mesoderm. (iv) Interactions within neural plate with posterior dominance. Unfortunately, almost all the observable markers are in the CNS rather than in the mesoderm where the initial specification is thought to occur. This has meant that the specification of the mesoderm has been assayed indirectly by transplantation methods such as the Einsteckung. New molecular markers now supplement morphological ones but they are still mainly in the CNS and not the mesoderm. A particular interest attaches to the genes of the Antp-like HOX clusters since these may not only be markers but actual coding factors for anteroposterior levels. We have a new understanding of mesoderm induction based on the discovery of activins and fibroblast growth factors (FGFs) as candidate inducing factors. These factors have later consequences for anteroposterior pattern with activin tending to induce anterior, and FGF posterior structures. Recent work on neural induction has implicated cAMP and protein kinase C (PKC) as elements of the signal transduction pathway and has provided new evidence for the importance of tangential neural induction. The regional specificity of neural induction has been reinvestigated using molecular markers and provides conclusions rather similar to the classical work. Defects in the axial pattern may be produced by retinoic acid but it remains unclear whether its effects are truly coordinate ones or are concentrated in certain regions of high sensitivity. In general the molecular studies have supported and reinforced the "pre-molecular ones". Important questions still remain: (i) How much pattern is there in the mesoderm (how many states?) (ii) How is this pattern generated by the invaginating organizer? (iii) Is there one-to-one transmission of codings to the neural plate? (iv) What is the nature of the interactions within the neural plate? (v) Are the HOX cluster genes really the anteroposterior codings?


LFB1 and LFB3 homeoproteins are sequentially expressed during kidney development.

LFB1 (HNF-1/HNF-1 alpha/APF) and LFB3 (vHNF-1/HNF-1 beta) are two homeoproteins involved in the transcriptional regulation of several liver-specific genes. Both genes are expressed in the polarized epithelia of a wide range of tissues, including liver, the digestive tract and kidney. We have analyzed the expression pattern of LFB1 and LFB3 in the developing rat kidney by in situ hybridization. Our results show that LFB3 transcripts can be detected in mesoderm-derived cells as soon as they are induced to differentiate into a polarized epithelium, while LFB1 transcripts appear only at a later stage when the three different segments of the nephron become apparent. LFB1 transcripts are restricted to the proximal and distal tubules, whereas LFB3 is also detected in the collecting ducts. Neither LFB1 nor LFB3 are expressed in the glomeruli or in the transition epithelia of the ureters and of the urinary bladder, none of which are involved in active transport mechanisms. The sequential activation of these two genes is also observed in transfilter organ cultures of nephrogenic mesenchyme at different stages after induction. This expression pattern suggests that LFB3 and LFB1 play a role in two critical stages of the developmentally regulated conversion of the nephric mesenchyme into a polarized epithelium: the early inductory phase (LFB3) and the postinductory phase (LFB1+LFB3).


Ten different Polycomb group genes are required for spatial control of the abdA and AbdB homeotic products.

Mutations in genes of the Polycomb (Pc) group cause abnormal segmental development due to ectopic expression of the homeotic products of the Antennapedia and bithorax complexes. Here the requirements for Pc group genes in controlling the abdA and AbdB products of the bithorax complex are described. Embryos containing mutations in the genes Polycomb (Pc), extra sex combs (esc), Enhancer of zeste [E(z)], polyhomeotic (ph), Sex comb on midleg (Scm), Polycomb-like (Pcl), Sex comb extra (Sce), Additional sex combs (Asx), Posterior sex combs (Psc) and pleiohomeotic (pho) were examined. In every case, both abdA and AbdB are expressed outside of their normal domains along the anterior-posterior (A-P) axis, consistent with these Pc group products acting in a single pathway or molecular complex. The earliest detectable ectopic expression is highest in the parasegments immediately adjacent to the normal expression boundary. Surprisingly, in the most severe Pc group mutants, the earliest ectopic AbdB is distributed in a pair-rule pattern. At all stages, ectopic abdA in the epidermis is highest along the anterior edges of the parasegments, in a pattern that mimics the normal abdA cell-specific pattern. These examples of highly patterned mis-expression show that Pc group mutations do not cause indiscriminate activation of homeotic products. We suggest that the ectopic expression patterns result from factors that normally activate abdA and AbdB only in certain parasegments, but that in Pc group mutants these factors gain access to regulatory DNA in all parasegments.


Plasmodium falciparum: characterization of gene R45 encoding a trophozoite antigen containing a central block of six amino acid repeats.

We describe here an antigen, called R45, expressed by the young trophozoites of Plasmodium falciparum. This antigen contains a block of tandem repeats of six amino acids which are recognized by sera from humans living in endemic areas. The R45 gene is located on chromosome 3. It is present in all strains examined and shows limited size polymorphism. The C-terminal unique region of the protein shows a strong homology with the catalytic domain of the serine protein kinases. Interestingly, the central repeats contain a large number of putative phosphorylation sites. The implications of these features are discussed.


IL2- and IL4-dependent proliferation of T-cell clones derived early after allogeneic bone marrow transplantation: studies of patients with chronic myelogenous leukaemia.

In an attempt to explore T-cell functions shortly after allogeneic bone marrow transplantation more fully, IL2- and IL4-dependent proliferation was assessed on CD4+ TCR alpha beta+ T-cell clones derived 4-6 weeks after transplantation. Both allogeneic pooled peripheral blood mononuclear cells and Epstein-Barr virus-transformed B-cell lines (BCL) could function as accessory cells (AC) for PHA activation of T-cell clones. Although minimal clonal proliferation was seen when the T-cell activation signal was BCL+PHA+IL4, a majority of the clones could undergo IL4-dependent proliferation after previous activation with AC+PHA+IL2. For certain clones, IL4 also showed an additive effect with IL2. Thus, IL4 was a growth factor for a majority of the investigated posttransplant T-cell clones, and in vivo modulation of IL4-dependent T-cell functions may thus become a future therapeutic possibility to enhance graft-versus-leukaemia effects in bone marrow transplant recipients.


Postterm pregnancy: computer analysis of the antepartum fetal heart rate patterns.

The purpose of this study was to establish reference ranges for numerical fetal heart rate (FHR) data in postterm pregnancy and to compare them with the patterns of fetuses under undisturbed condition at term. FHR was analysed on-line by Sonicaid Computer System 8000. A statistically significant decrease in the number of accelerations and decrease of variation in postterm pregnancy was observed. The duration of high variation (high episodes) in the 42nd week of gestation was statistically lower than in the pregnancy at term. These observations should be taken into account by clinicians in the interpretation of FHR records in postterm pregnancy.


Is 2-propyl-4-pentenoic acid, a hepatotoxic metabolite of valproate, responsible for valproate-induced hyperammonemia?

To investigate the association between valproate metabolism (VPA) and VPA-induced hyperammonemia together with the contribution of VPA hepatotoxicity risk factors such as young age, polypharmacy, and high serum VPA levels to VPA-induced hyperammonemia, plasma ammonia (NH3) levels, serum levels of VPA and its metabolites, and biochemical parameters were determined in 98 patients treated with VPA (53 monopharmacy cases and 45 polypharmacy cases). In monopharmacy patients, plasma NH3 levels did not depend on age, VPA dosage or serum levels. Serum level of 2-propyl-4-pentenoic acid (4-en) showed a negative correlation with plasma NH3 level in the monopharmacy group. In polypharmacy patients, plasma NH3 levels, serum glutamic pyruvic transaminase, and gamma-glutamyl-transpeptidase were significantly higher, while level/dose VPA ratio, 2-en-VPA serum level, and bilirubin were significantly lower than those in monopharmacy patients. These results suggest that young age and relatively high VPA serum levels within the therapeutic range were unlikely to be risk factors for common hyperammonemia associated with VPA therapy and that 4-en was not causally related to this adverse effect. The decreased serum level of 2-en-VPA in polypharmacy patients may be a reflection of a certain mitochondrial dysfunction, which might be a mechanism of the increased NH3 levels. The changes in biochemical parameters in polypharmacy patients were considered results of the enzyme-inducing activity of coadministered antiepileptic drugs (AEDs).


Placental malaria and pregnancy outcome.

Malaria parasitemia was assessed in 312 placentae of singleton deliveries in Benin. The prevalence rate was 45.19%. The dominant infecting specie was Plasmodium falciparum. High density parasitemia of placental smear in 44.68% was associated with preterm delivery, low birthweight, intrauterine growth retardation and neonatal mortality. Placental histological diagnosis of malaria in 57.69% was more frequently associated with intrauterine growth retardation. Extraplacental parasitemia decreased but intraplacental parasitemia increased with gestational age.


Prolonged pregnancy: the management dilemma.

In a prospective randomized study, pregnancies with unfavorable cervix and well established gestational age of at least 42 weeks were selected for management by either antepartum fetal testing or prostaglandin gel induction of labor. Of the 108 pregnancies studied, 57 (53%) had labor induced and 51 (47%) continued without intervention. Comparison of the two groups showed no difference in meconium staining, fetal distress, length of first stage of labor, the need for intervention, or the mode of delivery. In terms of Apgar score the neonatal outcome was not significantly different but a greater proportion of the babies (7.8% versus 1.8%) in the noninduced group required intubation. Our data show that there is no particular advantage in letting the pregnancy go beyond 42 completed weeks of gestation especially if prostaglandin is available for induction of labor.


The challenge of grandmultiparity in Nigerian obstetric practice.

A retrospective analysis of 733 Nigerian grandmultiparae seen at the University of Nigeria Teaching Hospital (UNTH) over a 3 year period was carried out. A high incidence of grandmultiparity (11%) was noted, and most of them (62%) belonged to the lower socioeconomic class. Anemia, hypertensive diseases, abruptio placentae, breech presentation and abnormal lie were significant complications of grandmultiparity. The incidence of multiple pregnancy, low birthweight babies, cesarean deliveries and perinatal deaths were markedly increased in the grandmultipara. Improvement in socioeconomic conditions of the populace, health education and widespread practice of family planning are suggested to reduce the incidence of grandmultiparity.


Ventriculoperitoneal shunt and pregnancy.

A pregnancy in a patient with ventriculoperitoneal (VP) shunt was recently managed at the authors's institution. Review of the literature showed only six previous case reports. The management of this uncommon neurosurgical condition in pregnancy is presented along with a review of the literature. We conclude that pregnancy in a patient with a VP shunt for maternal hydrocephalus, generally has a normal outcome and that the function of the shunt is unaffected by pregnancy.


A conservative surgical treatment of cervical pregnancy with active bleeding--uterine artery ligation and cervicotomy.

Cervical pregnancy complicated with massive bleeding usually results in abdominal hysterectomy, and thus the patient loses her fertility potential. Conservative management to control active hemorrhaging as well as to preserve reproductive function is necessary for women who desire more children. We present four patients with cervical pregnancy, complicated by life threatening hemorrhage, who were successfully treated with uterine artery ligation and cervicotomy. Subsequently, one patient had two successful term pregnancies delivered by cesarean section.


Recurrent leiomyoma of the vagina.

A rare case of huge vaginal leiomyoma recurrence is reported. Vaginal leiomyoma is a rare entity and recurrence after its removal is extremely rare. However, if recurrence occurs with intact ovarian function ovariectomy should also be done.


Intravenous leiomyomatosis with massive ascites.

A case of intravenous leiomyomatosis with massive ascites is reported. This is the first such recorded case. The patient was treated with a subtotal abdominal hysterectomy and bilateral salpingo-oophorectomy. Pathological examination established a vessel wall origin. There is no evidence of recurrence up to 20 months after initial treatment.


Bilateral and synchronous cervical carcinoma in situ in a didelphic uterus.

A case is reported of a bilateral and synchronous cervical squamous cell carcinoma in situ in a patient with uterus didelphys. Bilateral simultaneous conizations of both cervices were curative. Theories of tumor origin in such a case are discussed.


Proximal tubal obstruction associated with tubal schistosomiasis.

The gynecologic consequences of schistosomiasis may range from minimal inflammation of tubal serosa to more intense reactions involving the periadnexal regions. Complete obliteration of the tubal lumen has not been described. We describe a case of proximal tubal obstruction associated with tubal schistosomiasis.


A new nonsurgical technique for termination of intrauterine pregnancy associated with large multiple uterine leiomyomas.

Medical termination of a first trimester intrauterine pregnancy associated with large and multiple leiomyomas posed a unique problem because the sac was inaccessible per vaginum for surgical or vacuum evacuation. The use of prostaglandins was contraindicated due to a past history of bronchial asthma. But intraamniotic and intraplacental instillation of methotrexate, 25 mg at each site, under ultrasound guidance resulted in termination of pregnancy. No side effects or complications were observed after the procedure.


Safety of oral contraceptives for teenagers. ACOG Committee opinion: Committee on Adolescent Health Care number 90--February 1991.

By age 18, 51% of adolescent women will be sexually active. Oral contraceptives are a safe method to avoid the potentially disastrous outcome of an unwanted pregnancy. The overall risks of taking oral contraceptives are much less than the risks of pregnancy (20). Specifically, the risks associated with the use of oral contraceptives by teenagers are negligible. Low-dose oral contraceptives have not been linked with either heart attack or stroke in contemporary U.S. studies. While the risk of thromboembolism in oral contraceptive users as a whole may be increased over that of the general population, the risk to teenagers, especially those who do not smoke, is minimal. The risk of death from oral contraceptive use for teenagers is virtually nil (12). As with all medical choices, the benefits of a treatment must be weighed against any potential risks. For adolescents, the benefits associated with the use of oral contraceptives outweight the risks, particularly those of pregnancy. However, teenagers at risk for sexually transmitted diseases should be advised to use a barrier method along with oral contraceptives.


Role of alpha-adrenoceptors in the effects of buspirone and 5-carboxamidotryptamine in rabbit isolated thoracic aorta.

1. The role of alpha-adrenoceptors in the vascular effects of buspirone (BUS) and 5-carboxamidotryptamine (5-CT) was investigated in rabbit thoracic aorta. 2. Buspirone produced a concentration-dependent contraction. The non-selective 5-HT1 and 5-HT2-receptor antagonist methysergide and the 5-HT2 receptor antagonist ketanserin did not alter the contractile effect of buspirone. However, the competitive antagonist of alpha 1-adrenoceptors, prazosin, shifted the concentration-response curve of buspirone to the right without changing the maximal response. 3. Benextramine tetrahydrochloride monohydrate (BHC), a noncompetitive antagonist of alpha 1-adrenoceptors, inhibited the contraction induced by buspirone in a noncompetitive manner. After pretreatment with two different concentrations of BHC, the estimated apparent dissociation constants of buspirone were found to be identical. 4. In addition, buspirone antagonized the concentration-response curve of phenylephrine again showing a similar dissociation constant, suggesting a partial agonistic action of buspirone at the level of alpha 1-adrenoceptors. 5. The concentration-response curve of 5-HT showed two components in the thoracic aorta obtained from reserpine treated and untreated animals as verified by different pD2 values. The second component was observed with relatively higher concentrations of 5-CT and could be blocked by prazosin or BHC. Neither of these compounds altered the first component. After Pretreatment with BHC, the first component of 5-CT was competitively antagonized by methysergide and ketanserin, having pA2 values of 8.81 and 9.1 respectively. 6. These results suggest that the contraction induced by buspirone is mainly mediated by alpha 1-adrenoceptors, while the higher concentrations of 5-CT caused contraction via alpha 1-adrenoceptor stimulation in addition to its 5-HT2 agonistic effect.


Global population genetic structure and male-mediated gene flow in the green turtle (Chelonia mydas): RFLP analyses of anonymous nuclear loci.

We introduce an approach for the analysis of Mendelian polymorphisms in nuclear DNA (nDNA), using restriction fragment patterns from anonymous single-copy regions amplified by the polymerase chain reaction, and apply this method to the elucidation of population structure and gene flow in the endangered green turtle, Chelonia mydas. Seven anonymous clones isolated from a total cell DNA library were sequenced to generate primers for the amplification of nDNA fragments. Nine individuals were screened for restriction site polymorphisms at these seven loci, using 40 endonucleases. Two loci were monomorphic, while the remainder exhibited a total of nine polymorphic restriction sites and three size variants (reflecting 600-base pair (bp) and 20-bp deletions and a 20-bp insertion). A total of 256 turtle specimens from 15 nesting populations worldwide were then scored for these polymorphisms. Genotypic proportions within populations were in accord with Hardy-Weinberg expectations. Strong linkage disequilibrium observed among polymorphic sites within loci enabled multisite haplotype assignments. Estimates of the standardized variance in haplotype frequency among global collections (FST = 0.17), within the Atlantic-Mediterranean (FST = 0.13), and within the Indian-Pacific (FST = 0.13), revealed a moderate degree of population substructure. Although a previous study concluded that nesting populations appear to be highly structured with respect to female (mitochondrial DNA) lineages, estimates of Nm based on nDNA data from this study indicate moderate rates of male-mediated gene flow. A positive relationship between genetic similarity and geographic proximity suggests historical connections and/or contemporary gene flow between particular rookery populations, likely via matings on overlapping feeding grounds, migration corridors or nonnatal rookeries.


New molecular markers for the distal end of the t-complex and their relationships to mutations affecting mouse development.

Many mutations affecting mouse development have been mapped to the t-complex of mouse chromosome 17. We have obtained 17 cosmid clones as molecular markers for this region by screening a hamster-mouse chromosome 17 and 18 cell hybrid cosmid library with mouse-specific repetitive elements and mapping positive clones via t-haplotype vs. C3H restriction fragment length polymorphism (RFLP) analysis. Twelve of the clones mapping distal to Leh66B in t-haplotypes are described here. Using standard RFLP analysis or simple sequence length polymorphism between t-haplotypes, exceptional partial t-haplotypes and nested sets of inter-t-haplotype recombinants, five cosmids have been mapped in or around In(17)3 and seven in the most distal inversion In17(4). More precise mapping of four of the cosmids from In(17)4 shows that they will be useful in the molecular identification of some of the recessive lethals mapped to the t-complex: two cosmids map between H-2K and Crya-1, setting a distal limit in t-haplotypes for the position of the tw5 lethal, one is inseparable from the tw12 lethal, and one maps distal to tf near the t0(t6) lethal and cld.