[Na K ATPase activity and pulmonary hemodynamics in the development of arterial hypertension]. A total of 116 subjects with borderline hypertension, 67 relatives of normotensive probands and 29 relatives of hypertensive probands were examined. The activity of Na,K-ATPase in the red blood cells and pulmonary hemodynamics were studied by kinetocardiography. The normotensives with a family history of essential hypertension and subjects with borderline hypertension were found to have elevated pulmonary systolic pressure. The changes were coupled to lower erythrocyte Na,K-ATPase activity, which seems to suggest that endogenous ouabain-like factor that inhibits the enzymatic activity is present in plasma.


[Comparative anti-arrhythmia effectiveness of activators of body stress-limiting systems in patients with arrhythmia]. The antiarrhythmic effects produced by activators of the body's stress-limiting systems were comparatively evaluated in patients with cardiac arrhythmias of ischemic and non-ischemic etiology. Acediprol, gidazepam, and befol were found to be beneficial in ventricular premature contraction when psychoemotional stress was simulated, as evidenced by 24-hour monitoring. The most pronounced protective therapeutical effect of the drugs was observed in patients with arrhythmias of extracoronary origin and in individuals with a marked arrhythmogenic effect of stress. Gidazepam was shown to suppress the provocative arrhythmogenic effect of the stress test.


[Characteristics of the dynamics of rapid changes in blood phosphoinositides in patients with alcoholic heart diseases]. A total of 42 patients who had been abusing alcoholic beverages during different periods and 12 healthy individuals were examined. Their intracardiac hemodynamic parameters were evaluated by echocardiography and rapid changes in inositol-containing blood lipids were determined by thin-layer flow chromatography. The patients showed significantly reduced contractility of the left ventricle, its wall hypertrophy and greater cavity dimensions. These abnormalities were more pronounced in patients with an over 10-year history. Biochemical studies revealed a time course of rapid changes in inositol-containing lipids in patients, which showed more fluctuations in the content of phosphoinositides and their lower baseline and final levels and differed from that in healthy persons. It was stressed that the changes in inositol-containing lipids were also related to the duration of alcohol abuse and they reflected the mechanisms of the toxic action of ethanol on the myocardium, which might be useful in the assessment of the severity of cardiovascular events in alcoholism.


Dietary fatty acid modulates glomerular atrial natriuretic peptide receptor. Modification of dietary fatty acid (FA) has been shown to affect the incidence of hypertension and coronary artery disease. We studied whether these effects involve changes in the receptor characteristics of vasoactive substance. Characteristics of atrial natriuretic peptide (ANP) receptors were examined in glomeruli isolated from rats fed a diet containing 5% in weight omega 6, 5% omega 3, 20% omega 6, 20% omega 3 polyunsaturated FA or 20% saturated FA (SFA) for greater than 4 weeks. The FA composition of phospholipids in isolated glomeruli showed an elevation in 20:4 omega 6 (arachidonic acid, AA) in 5% omega 6, 20% omega 6 and 20% SFA, and elevations in 20:5 omega 3 (eicosapentaenoic acid, EPA) in 5% omega 3 and 20% omega 3 groups. The radioligand binding study revealed: (1) in 20% FA group, receptor density (Ro, fmol/mg prot) of ANP was significantly decreased compared to 5% group (262 +/- 13, n = 8 to 120 +/- 13, n = 12) without changes in equilibrium dissociation constant (KD), (2) among high FA (20%) groups, type of FA was essential for determining Ro; higher omega 6 was associated with a lower ANP Ro (177 +/- 11 vs. 103 +/- 3 fmol/mg prot, P less than 0.05) and KD (0.43 +/- .04 vs. 0.27 +/- .02 nM, P less than 0.05). To examine whether the alteration in receptor characteristics is mediated by FA, effects of FA were examined in vitro. In cultured mesangial cells, AA, but not EPA, decreased Ro of ANP receptors (48.7 +/- 4.8% of control, P less than 0.05) without affecting KD.(ABSTRACT TRUNCATED AT 250 WORDS)


Altered membrane ionic permeability in a rat model of chronic renal failure. Acute elevations in intracellular adenosine 3',5'-cyclic monophosphate (cAMP) concentrations are known to increase ionic chloride permeability in diverse tissues. To determine if chronic endogenous increases in cAMP are associated with sustained alterations in membrane ionic permeabilities, renal cortical brush border membrane vesicles (BBMV) were prepared and red blood cells were harvested in a model of chronic renal failure, the 75% nephrectomized rat. Relative ionic permeabilities were determined using the potential-sensitive fluorescent probe 3,3'-dipropylthiadicarbocyanine iodide [diS-C3-(5)]. These studies demonstrate that renal cortical homogenate and RBC cAMP concentrations are increased in chronic renal failure animals. In the same animals relative ionic chloride permeability (PCl/PK) was significantly increased in renal cortical BBMV and RBC ghosts: PNa/PK was not affected. This selective change in permeability results in a significant increase in PCl/PNa and hyperpolarization of BBMV of sufficient magnitude to stimulate Na(+)-dependent glutamine transport. The change in glutamine uptake was not consequent to an alteration in the kinetics of glutamine transport or delayed dissipation of the inward Na+ gradient. Renal hypertrophy per se did not effect renal homogenate cAMP concentration or relative ionic permeability of renal cortical BBMV prepared from kidneys of uninephrectomized animals fed a 40% protein diet. These studies demonstrate that relative ionic chloride permeability and tissue [cAMP] are chronically increased in diverse cells (renal proximal tubule and RBCs) in a rat model of renal failure. These findings suggest that membrane ionic permeability may be altered and electrogenic transport secondarily perturbed in renal failure in association with hormonally-induced chronic elevations of intracellular cAMP concentrations.


Glycosaminoglycans prevent morphological renal alterations and albuminuria in diabetic rats. Abnormal glycosaminoglycan metabolism is involved in the onset of anatomo-functional derangements in diabetic nephropathy, and determines the loss of glomerular basement membrane anionic charges leading to albuminuria. Glycosaminoglycan administration was shown to increase the negative electrical potential of the vessel wall, inhibit mesangial cell proliferation, which is an anatomical hallmark of diabetic nephropathy, and slow down the progression to uremia in subtotally nephrectomized rats, a model that shares some pathogenetic key events with diabetic nephropathy. Based on these considerations, we verified the effect of exogenous glycosaminoglycans on renal involvement in streptozotocin diabetic rats. Long-term administration of two glycosaminoglycans (low-molecular weight heparin and dermatan sulphate) prevented glomerular basement membrane thickening, glomerular anionic charge reduction, as well as the onset of albuminuria without affecting glomerular filtration rate and metabolic control of the disease. Our data demonstrate that the long-term administration of glycosaminoglycans has a favorable effect on morphological and functional renal abnormalities in diabetic rats.


Tumor necrosis factor alpha increases antifibrinolytic activity of cultured human mesangial cells. Tumor necrosis factor alpha (TNF alpha) is likely to exert a major influence in the pathogenesis of glomerulopathies. Besides its proinflammatory properties. TNF alpha interacts with cell growth and synthesis of components of the fibrinolytic system. In this study, we report the effects of recombinant human TNF alpha on the synthesis of tissue-type plasminogen activator (t-PA) and its inhibitor (PAI-1) by human mesangial cells in culture. We first demonstrate that TNF alpha binds specifically to a single class of high affinity receptors (Kd 5.10(-11) M; 1500 receptors/cell). TNF alpha has an antimitogenic effect on human mesangial cells since it decreased DNA synthesis, measured by 3H-thymidine incorporation, in a dose-dependent manner. Release of cytosolic LDH and incorporated 51Cr was not increased by 100 ng/ml TNF alpha as compared with control, indicating that this monokine is not cytotoxic for cultured human mesangial cells. Zymographic analysis and reverse fibrin autography disclosed a 120 kD t-PA-PAI-1 complex and a 50 kD free form of PAI-1 in the supernatants of both unstimulated and TNF-stimulated cells; PAI-1 was released in excess and free t-PA was not observed. TNF alpha (0 to 100 ng/ml) had no effect on t-PA synthesis, but enhanced PAI-1 release in a time- and dose-dependent manner (97% increase of PAI-1 synthesis after a 24 hour incubation). This effect was abolished by cycloheximide, suggesting that protein synthesis was required. Northern blot analysis showed that TNF alpha increased the steady-state PAI-1 mRNA levels in a time-dependent manner, with a maximal effect at two hours.(ABSTRACT TRUNCATED AT 250 WORDS)


Possible mechanism of impaired calcium and vitamin D metabolism in nephrotic rats. Patients who have nephrotic syndrome and normal renal function are hypocalcemic in spite of the elevated levels of serum parathyroid hormone (PTH) caused by a low serum concentration of 1,25-dihydroxyvitamin D[1,25(OH)2D], presumably because of its loss in urine. However, it has not been established whether the conversion of 25-hydroxyvitamin D[25(OH)D] into 1,25(OH)2D is impaired in the kidney. In this study, we examined the serum levels of vitamin D metabolites, and kinetics of renal 25(OH)D-1-hydroxylase activity in vitro, and nephrogenous cyclic AMP excretion in response to exogenous PTH administration in puromycin aminonucleoside-induced nephrosis in rats. Plasma ionized calcium and the serum levels of vitamin D metabolites were lower, and conversely, the serum PTH level was higher, in nephrotic rats than in controls. Serum 1,25(OH)2D levels were higher in 25(OH)D3-treated nephrotic rats than in untreated nephrotic rats, indicating that the low 1,25(OH)2D level in nephrotic rats is partially due to the low concentration of 25(OH)D. Although PTH levels were higher in nephrotic rats than in control rats, the Vmax of renal 25(OH)D-1-hydroxylase and nephrogenous adenosine 3',5'-monophosphate (cyclic AMP) excretion in response to exogenous PTH were significantly lower in nephrotic animals than in controls. These results suggest that abnormalities in calcium and vitamin D metabolism in nephrotic rats are partially attributable to impaired proximal tubular function.


Chemoattractants provoke monocyte adhesion to human mesangial cells and mesangial cell injury. Infiltration of glomerular mesangium by monocytes/macrophages is a prominent pathologic finding in many forms of glomerulonephritis (GN). While the mechanism(s) by which infiltration occurs is incompletely understood, monocyte adhesion to glomerular endothelial cells, provoked by inflammatory mediators, appears to be an important early step. In the present study, we assessed the influence of chemotactic peptides (C5a) and lipids (LTB4 and PAF) on adhesion of human monocytes and mesangial cells, to determine if mesangial cells (glomerular pericytes with smooth muscle properties) represent potential targets for adhesion of chemoattractant-activated monocytes following their diapedesis from the intravascular space. C5a and LTB4 provoked rapid (onset less than 1 min) monocyte-mesangial cell adhesion at nanomolar concentrations via actions with monocytes, while PAF was less potent in this regard. Monoclonal antibodies (mAb) were used to define the monocyte and mesangial cell adhesion molecules involved in these interactions. C5a- and LTB4-induced monocyte adhesion was inhibited (approximately 54%) by mAb against the common beta CD18 subunit of CD11/CD18 leukocyte integrins, while mAb against monocyte L-selectin was without effect. MAb against unique CD11 subunits were used to determine the relative contributions of different CD11/CD18 integrins. In this regard, adhesion was inhibited by mAb against CD11b (approximately 41%), and CD11c (approximately 23%), but not CD11a. MAb against mesangial cell ICAM-1 afforded approximately 27% reduction in adhesion, while mAb against VCAM-1, E-selectin, and P-selectin were without effect. GM-CSF, a cytokine generated by monocytes and mesangial cells, also provoked CD11/CD18-dependent adhesion, and primed monocytes to the actions of chemoattractants.(ABSTRACT TRUNCATED AT 250 WORDS)


Plasma tumor necrosis factor soluble receptors in chronic renal failure. Two soluble tumor necrosis factor receptors (sTNFRs) were detected in the plasma of patients with different degrees of chronic renal failure (CRF) and of long-term hemodialysis (HD) patients. In uremic undialyzed patients, plasma levels of both sTNFRs increased progressively with declining renal function. A linear correlation was found between sTNFR plasma levels and plasma creatinine concentration. sTNFR levels in end-stage uremic patients shortly before commencement of first HD treatment were approximately tenfold higher than in normal subjects. Long-term HD patients showed a further increase in plasma sTNFRs. The origin of sTNFRs, as well as their physiological role remains to be elucidated.


Abnormal cytoplasmic pH regulation during activation in uremic neutrophils. Neutrophils isolated from ESRF patients demonstrated abnormal cytoplasmic pH changes after FMLP stimulation; the initial cytoplasmic acidification was absent (P less than 0.001 compared to controls) and the degree of alkalinization enhanced (P less than 0.05 compared to controls). This effect was not due to the absence of any of the factors associated with acidification in normal PMN since superoxide production was enhanced (P less than 0.05 compared to controls) and intracellular calcium release was normal. Our observations are not explicable by alterations in the function of the Na:H antiport since the kinetics of antiport activation by cytoplasmic pH were not different in uremic and control cells. Other factors must therefore be important in generating the abnormal pH response to chemotactic factors in uremic PMN. Cells from CAPD patients had some degree of initial acidification (P less than 0.001 compared to controls and P less than 0.05 compared to ESRF) and enhanced alkalinization (P less than 0.05 compared to controls). Preincubation of normal PMN in four-hour dwell PDE reproduced the responses of uremic PMN with absent acidification, enhanced alkalinization and enhanced superoxide generation after FMLP stimulation (P less than 0.05 compared to controls). Changes in the control of cytoplasmic pH in stimulated PMN may influence PMN function, and our observations may be relevant to the susceptibility of uremic patients to infection.


Interleukin-1 and tumor necrosis factor and their naturally occurring antagonists during hemodialysis. Cytokines are polypeptides which possess various biological properties affecting host defense function and response to disease. Two cytokines, interleukin-1 (IL-1) and tumor necrosis factor (TNF) induce fever, hypotension and inflammation when injected into animals or human subjects. In humans injected with either IL-1 or TNF, sleepiness, generalized myalgias and headache are commonly reported. Therefore, the production of IL-1 and TNF as a consequence of hemodialysis was hypothesized to explain, in part, the signs and symptoms of the dialysis patient. Laboratory studies confirmed that the activation of complement and the passage of microbial products from the dialysate into the blood compartment induces the synthesis of IL-1 and TNF. Although elevated production of IL-1 and TNF in the mononuclear cells and in the circulation of patients during and after hemodialysis have been reported, these levels have not been a consistent finding and are low compared to the amount of dialysis related symptoms. Recent studies, however, demonstrate that IL-1 and TNF have naturally occurring antagonists which specifically block the biological activities of these two cytokines. The IL-1 receptor antagonist blocks IL-1 binding to cells but has no IL-1 activity of itself. Soluble TNF receptors prevent TNF from binding to its cellular receptors and hence serve as anti-TNF mechanisms. These inhibitors are currently in clinical trials for sepsis where efficacy has been demonstrated; however, the IL-1 receptor antagonist (IL-1Ra) and soluble TNF receptors (sTNFR) are likely candidates for use in dialysis patients with symptomatic hypotension. Although levels of IL-1Ra and sTNFR are elevated in patients on HD, these levels reflect the host response to inflammation. It is unclear whether acute or chronic administration of IL-1Ra or sTNFR will be beneficial in treating some of the acute or chronic changes seen in dialysis patients.


[Complications of acute respiratory tract infection (pneumonia, sinusitis) in young children associated with acute HHV 6 infection]. The human herpesvirus-6 (HHV-6) causes exanthema subitum ("e.s."). "E.s." is characterized by fever, exanthem (rash), in many cases gastroenteritis, occasionally cerebral convulsions (but more frequently general cerebral irritability) and enlargement of all lymph nodes; usually there are mild catarrhal respiratory symptoms of the upper airways (ARD). So-called "complications" of an ARD (pneumonia, acute purulent otitis media, acute sinusitis) due to bacterial infections are very unusual as sequelae of a HHV-6 infection. Here we report the case of 2 small children (toddlers) suffering from bronchopneumonia or pneumonia and acute sinusitis maxillaris associated with an acute HHV-6 infection. It seems that HHV-6 (like other respiratory tract viral pathogens) also can lead to secondary bacterial infections of the lower respiratory tract. So far it is not known, why such complications are so rare, although the extreme granulocytopenia accompanying "e.s." suggests a transient disturbance of the antibacterial defence mechanisms.


Sclerosing hepatocellular carcinoma with hypercalcemia--a case report. A case of sclerosing hepatocellular carcinoma (SHCC) with hypercalcemia was reported. Clinical studies revealed a tumor at the liver hilum with invasion into the bile duct. Light microscopy of the tumor disclosed a moderately differentiated hepatocellular carcinoma (HCC) of the trabecular type with diffuse fibrous stroma. Abundant dense granules were observed in the cytoplasm of the tumor cells with electron microscopy. The elevated serum calcium (13.9 mg/dl) returned to the normal range after resection of the tumor.


Detection of human papillomavirus (HPV) infections in Japanese women with and without abnormal cervical cytology by dot blot and Southern blot hybridization. The frequency of human papillomavirus (HPV) was investigated in 245 Japanese women (100 showing normal cytology and 145 showing abnormal cytology). A previously presented method for the detection and typing of HPV DNA was used, where a dot blot test excluded samples that did not hybridize with HPV DNA. Positive samples were further analyzed by a southern blot procedure, to give the HPV type. A mixture of subgenomic probes of the types 6, 11, 16, 18, 31, 33 and 35 was used. HPV DNA was detected in only 2% (2/100) of patients without abnormal cytology. In patients with abnormal cytology, the frequency was 30% (43/145). HPV was detected in 100% (2/2) of the patients with condyloma acuminatum, 39% (26/66) of those with mild to moderate dysplasia, 44% (7/16) of those with severe dysplasia to carcinoma in situ, and 70% (7/10) of those with invasive carcinoma. Young women (20-29 yr.) had the highest HPV frequency (71%). HPV types 16 and 18 were found in 39% of the patients with mild to moderate dysplasia, in 71% of those with severe dysplasia to carcinoma in situ and in 86% of those with invasive carcinoma. These may be considered as high risk types for development to cancer. HPV type 31 may be considered as a moderate risk, as it was detected in 37% (16/43) of the patients. HPV types 6 and 11 were found in 100% of patients with condyloma acuminatum (2/2). To clarify the natural history of the HPV infection in the uterine cervix, it is necessary to conduct further studies.


Evidence for transforming growth factor-beta expression in human leptomeningeal cells and transforming growth factor-beta-like activity in human cerebrospinal fluid. Little is known about the factors regulating growth and maintenance of human leptomeningeal cells. The influence of cerebrospinal fluid on these functions is also unknown. Possible mediators include the transforming growth factor-beta (TGF beta) family, three closely related peptides that regulate proliferation and numerous other physiologic processes in most mesenchymal cells. Expression of both mRNA and protein for TGF beta isoforms TGF beta 1, TGF beta 2, and TGF beta 3 as well as TGF beta-competing activity were evaluated in primary human leptomeningeal cultures by Northern blot analysis, immunohistochemistry, and a radioreceptor assay, respectively. TGF beta 1, TGF beta 2, and TGF beta 3 immunoreactivity was also evaluated in brain sections containing leptomeninges from which these cell cultures were established. An additional study analyzed human cerebrospinal fluid for TGF beta-like activity. Transcripts for TGF beta 1, TGF beta 2 and TGF beta 3 were detected in RNA from each of the eight leptomeningeal cultures. Significant TGF beta 1 immunoreactivity was detected in leptomeningeal tissue from five of eight cases. TGF beta 2 and TGF beta 3 immunostaining was seen in eight and seven of the cases, respectively. Similarly, cells cultured from these meninges exhibited variable TGF beta 1 and extensive TGF beta 2 and TGF beta 3 immunoreactivity. Radioreceptor assays of conditioned media from four cultures demonstrated significant latent TGF beta-like activity. TGF beta radioreceptor competing activity was also detected by radioreceptor assay in normal blood-free cerebrospinal fluid from 32 patients without neurological disease. In addition, pooled cerebrospinal fluid (from six additional patients) exhibited dose dependent TGF beta-like activity in the radioreceptor assay, stimulation of AKR-2B cell growth in soft agar and inhibition of growth in CCL-64 cell assays suggesting that cerebrospinal fluid contains TG beta-like activity. These findings suggest that the human leptomeninges synthesize TGF beta 1, TGF beta 2 and TGF beta 3 and secrete latent TGF beta s at least in vitro. Human cerebrospinal fluid may also contain TGF beta isoforms. Collectively, these observations raise the possibility that members of the TGF beta family contribute to biologic processes of the leptomeninges.


Experimental IgA-IgG nephropathy induced by a viral respiratory pathogen. Dependence on antigen form and immune status. The etiology of IgA nephropathy (IgAN), the most common form of glomerulonephritis in the world, remains an enigma. Episodes of nephritis are frequently preceded by acute viral respiratory syndromes, but few experimental models associated with acute viral infection exist. An animal model of IgAN involving Sendai virus, a rodent parainfluenza virus similar to many human respiratory viruses, is described. Mice were either naturally infected or chronically mucosally immunized with virus. Immunized mice were then challenged intravenously with various physical forms of antigen to simulate viremia or antigenemia secondary to acute viral exposure. Twenty-four hours after challenge of immunized mice or 10 days after natural infection, mice were sacrificed. Anti-viral antibody titers, glomerular immune deposits, and glomerular function were evaluated. Chronic mucosal immunization of mice with Sendai virus resulted in a vigorous serum IgA (and IgG) anti-viral immune response, associated with comparable degrees of IgA, IgG, IgM, and antigen deposits in the glomeruli of both challenged and unchallenged mice. Only immunized, challenged mice developed significant proteinuria and hematuria. Neither deposits nor glomerular dysfunction was seen in controls. The physical form of antigen was important for altered glomerular function; although immunized mice challenged with either live or dead virions had a high incidence of hematuria, mice challenged with purified viral glycoproteins did not, even though all mice exhibited comparable immune deposits. Significant deposits of C3 were not present and were not required for glomerular injury. Finally, naturally infected mice exhibited a milder form of IgAN without hematuria. The experimental conditions for acute exposure to a natural viral respiratory pathogen of mice leading to IgAN are described. This model may be useful both to probe infection-related IgAN, and to facilitate the understanding of the various mechanisms responsible for IgAN.


Immunohistochemical localization of receptors for vasoactive intestinal peptide and substance P in human trachea. Tissue sections of human cervical trachea were processed for immunohistochemical demonstration of receptors for substance P [using an anti-SP anti-idiotypic antiserum directed toward the ligand binding site of the receptor (Couraud J-Y, Escher ED, Regoli D, Imhof V, Rossignol B, Pradelles P. Anti-substance P anti-idiotypic antibodies: Characterization and biological activities. J Biol Chem 1985;260:9461-9; Couraud J-Y, Maillet S, Grassi J, Frobert Y, Pradelles P. Characterization and properties of anti-substance P antiidiotypic antibodies. Methods Enzymol 1989; 178:275-300)] and vasoactive intestinal peptide (VIP; utilizing a monoclonal antibody toward VIP receptors of an adenocarcinoma cell line (Pichon J, Hirn M, Muller J-M, Mangeat P, Marvaldi J. Anticell surface monoclonal antibodies which antagonize the action of VIP in a human adenocarcinoma cell line (HT29). EMBO J 1983;2:1017-22)], respectively. Mucus cells of the submucosal glands (identified by periodic acid Schiff staining) and neuroendocrine cells of the respiratory epithelium (identified by immunoreactivity to protein gene product 9.5) displayed intense VIP receptor-immunoreactivity. Other tissue components known to respond to exogenously administered VIP, e.g., trachealis muscle, lacked VIP receptor-immunoreactivity, indicating that the monoclonal antibody did not label all receptor subtypes. In accordance with the known pharmacological actions of substance P upon the airways, the anti-substance P receptor antibody labeled the trachealis muscle, submucosal glands, and respiratory epithelium, predominantly at the luminal aspect. Since substance P as well as the structurally related tachykinin, neurokinin A, competed with the anti-receptor antibody in binding to the tissue section, it is likely that both NK-1 and NK-2 receptor subtypes were labeled. The present histochemical approach to localize peptide receptors in the trachea allowed precise analysis of distribution unreached by previous studies using autoradiography. Together with pharmacological data, these morphological findings contribute to the understanding of the sequences of events evoked by the neuropeptides, substance P and VIP, in the human trachea.


Isolation of a gastric phosphoprotein which stimulates acid secretion. Stimulation of gastric acid secretion is mediated by cAMP which regulates the proton pump through an A-kinase-dependent phosphoprotein. The purpose of this study was to isolate a stimulation-dependent gastric phosphoprotein capable of stimulating acid secretion. Gastric glands were prepared from rabbit gastric mucosa and acid secretion was stimulated with cAMP. A detergent extract of these stimulated gastric membranes was fractionated by gel chromatography and assayed for functional activity by measurement of [14C]-aminopyrine accumulation in permeabilized resting gastric glands or measurement of H(+)-K(+)-ATPase activity in inhibited gastric microsomes. We hereby report isolation of a membrane-bound, A-kinase-dependent phosphoprotein which enhances aminopyrine accumulation in digitonin-permeabilized gastric glands (32%) and stimulates H(+)-K(+)-ATPase activity in gastric microsomes to a level 55% of the maximal stimulation observed in the presence of valinomycin. Incubation of this phosphoprotein with [32P]ATP and the catalytic subunit of A-kinase resulted in [32P] incorporation into a protein which coincided with a single protein band on SDS-PAGE (17,500 Da).


Platelet activating factor alters receptor-coupled function in the isolated perfused rat heart. Sepsis induces primary myocardial dysfunction. Yet, both hyper- and hypodynamic cardiac states characterize the sepsis syndrome, suggesting a modulatory role of septic mediators. Platelet activating factor (PAF), implicated in the pathogenesis of sepsis, is an endogenous phospholipid with diverse intracellular and extracellular effects. The purpose of this study was to investigate the influence of PAF (1) upon basal mechanical function of the heart, (2) upon receptor-coupled function of the heart, and (3) on basal and stimulated myocardial function at differing concentrations. In order to focus on the relationship between PAF and cardiac mechanical function, rat hearts were isolated and crystalloid perfused using a modified Langendorf preparation. Separate hearts received intracoronary vehicle (5% ethanol, 2.5% BSA) or PAF (20 or 40 microM) as a bolus, followed 10 min later by 0.25 microM isoproterenol (beta-receptor agonist) infusion over 3 min. Both 20 and 40 microM PAF produced a rapid decrease in rate pressure product (RPP = HR X LVDPmax) relative to control (P < 0.05). The depressive effect of PAF upon basal myocardial function did not persist and by 10 min RPP was not different (P > 0.05) among the groups. Isoproterenol infusion increased (P < 0.05) RPP in all groups. However, hearts pretreated with 20 microM PAF demonstrated a greater (P < 0.05) response to beta-adrenergic stimulation relative to vehicle-pretreated controls. This amplified response to isoproterenol was not observed with pretreatment at a higher concentration of PAF (40 microM, P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)


Recent advances in the role of reactive oxygen intermediates in ischemic injury. I. Evidence demonstrating presence of reactive oxygen intermediates; II. Role of metals in site-specific formation of radicals. This article has attempted to bring the reader up to date on advances in selected facets of the area of reactive oxygen intermediate-induced ischemic injury. Specifically, we have discussed the more recent reports that provide evidence for the presence of these species in reperfused ischemic tissue. In addition, we have attempted to introduce the reader to the relatively new concept of "site-specific" formation of radicals and how the use of "push-pull" techniques, such as chelation by high-affinity chelators or displacement by non-redox-active metals such as zinc, may decrease postischemic reperfusion injury. Finally, we have identified a class of compounds that affect the oxidation state of redox-active metals, and have demonstrated how these compounds may also represent a new therapeutic modality. In conclusion, both academic and nonacademic surgeons should have profited from reading this article. For the academic surgeon, who may do research, several new cytoprotectants requiring further study in both in vitro and in vivo models have been identified. For the nonacademic surgeon in clinical practice the realization that there are several promising areas of research that may yield new therapies to mitigate postischemic reperfusion injury should have been gained.


Targeting cancer chemotherapy using a monoclonal antibody (NCC-LU-243) conjugated with mitomycin C. Two kinds of immunoconjugate (T-3M and T-11M) of murine monoclonal antibody with mitomycin C (MMC) were developed using spacers containing a disulfide (T-3M) or thiocarbamate (T-11M) bond. A murine monoclonal antibody (NCC-LU-243) raised against a human small cell lung carcinoma cell line, Lu-24, in nude mice, is an IgG2a monoclonal antibody that recognizes a 145-kDa protein on the cell surface membrane. T-3M and T-11M showed affinity for the LU-243 antigen-positive H-69 cell line but not for the antigen-negative Lu-65 cell line in vitro. In the in vitro MTT assay, the order of efficacy of these compounds was T-11M > T-3M > MMC against antigen positive H-69 and T-11M = MMC > T-3M against antigen-negative K562. When antigen-positive H-69 was transplanted into nude mice for in vivo assay, the maximum tolerated dose of T-3M was twice as high than that of the parent compound MMC. Furthermore, T-3M showed higher antitumor activity against antigen-positive H-69 than MMC conjugated with a non-specific rabbit IgG in vivo. When the maximum tolerated doses of T-3M and MMC were administered to H-69-bearing nude mice, the effect of T-3M was superior to that of MMC, whereas no differences were observed between the antitumor activity of T-3M and MMC against antigen- negative MX-1, a human breast carcinoma. These two immunoconjugates of monoclonal antibody with mitomycin C are thought to be useful for targeting cancer chemotherapy against human small cell lung carcinomas.


Effects of chronic tachycardia-induced cardiomyopathy on the beta-adrenergic receptor system. Chronic supraventricular (or ventricular) tachycardia causes a dilated cardiomyopathy. Effective treatment requires ablation of the tachycardia using antiarrhythmic agents, cryoablation, electroablation, or surgical interruption/excision. However, the underlying pathophysiologic mechanisms responsible for the development of supraventricular tachycardia-induced cardiomyopathy have not been fully identified. We hypothesized that chronic supraventricular tachycardia is associated with significant changes in the beta-adrenergic system that may have implications for the pathophysiology and treatment of supraventricular tachycardia-induced cardiomyopathy. Accordingly, we examined the relationship between left ventricular function, plasma norepinephrine level, beta-receptor number and affinity, and response to a beta-agonist (isoproterenol) infusion in eight control pigs and eight pigs subjected to supraventricular pacing-induced tachycardia (240 beats/min for 3 weeks). Left ventricular function was measured using simultaneous echocardiography and catheterization. Left ventricular end-diastolic dimension and pressure increased in pigs with supraventricular tachycardia (5.1 +/- 0.4 cm and 27 +/- 2 mm Hg) versus control pigs (3.8 +/- 0.3 cm and 8 +/- 2 mm Hg), p < 0.05. Left ventricular fractional shortening decreased in supraventricular tachycardia (10 +/- 1%) versus control pigs (34 +/- 1%), p < 0.05. In addition, in the pigs with supraventricular tachycardia the fractional shortening versus left ventricular end-systolic stress relationship fell below the control relationship. Plasma norepinephrine level (measured by high-performance liquid chromatography) increased in pigs with supraventricular tachycardia (3592 +/- 1606 pg/ml plasma) versus control pigs (323 +/- 74 pg/ml plasma), p < 0.05. beta-Receptor number and affinity (measured by [3H]dihydroalprenolol binding) did not change in supraventricular tachycardia (98.6 +/- 11.5 fmol/mg protein and 7.2 +/- 1.1 nmol) versus control pigs (99.1 +/- 9.4 fmol/mg protein and 6.8 +/- 0.5 nmol). The response to isoproterenol infusion (10 micrograms/kg) in supraventricular tachycardia was blunted: the absolute increase in left ventricular peak (+)dP/dt was reduced in supraventricular tachycardia (833 +/- 233 mm Hg/sec) versus control pigs (2180 +/- 139 mm Hg/sec), p < 0.05. Chronic supraventricular tachycardia caused a decreased contractile state, increased plasma norepinephrine level, and caused no change in beta-receptor number or affinity; however, the response to beta-agonist infusion was blunted. These results suggest that chronic supraventricular tachycardia is associated with uncoupling of the beta-receptor from subsequent intracellular components of the beta-adrenergic system. Therefore medical management of chronic supraventricular tachycardia-induced cardiomyopathy before and immediately after definitive ablation may require use of pharmacologic agents whose actions do not depend on an intact beta-adrenergic pathway.


Most peripheral, node-negative, non-small-cell lung cancers have low proliferative rates and no intratumoral and peritumoral blood and lymphatic vessel invasion. Rationale for treatment with wedge resection alone. We investigated the tumor aggressiveness (intratumoral and peritumoral lymphatic and blood vessel invasion by tumor emboli) and proliferative activity (mitotic count) of 45 patients with peripheral, superficially seated, node-negative (T1-2 N0 M0), non-small-cell lung cancer treated with wedge resection alone between January 1982 and June 1988. Most patients were male (n = 39) with T1 (n = 25), small (mean diameter, 2.6 +/- 0.8 cm), squamous (n = 24), right-sided (n = 29) tumors located in either upper lobe (n = 35). The surgical specimens were studied by immunohistochemical staining with a monoclonal antibody targeting the factor VIII-related antigen. None of the tumors had lymphatic peritumoral or intratumoral invasion. Seven neoplasms (15%) harbored blood vessel invasion by tumor cells; all but one of these invasions were within the substance of the tumor. The median mitotic count was 8 mitoses per 10 high-power fields (range, 1 to 42 mitoses), significantly (p = 0.003) higher in patients with blood vessel invasion than in those without. With a 24-month minimum follow-up, projected 3- and 5-year survivals are 79% and 68%, respectively. Eleven patients had relapses and died of their tumors because of either local (n = 5) or extrathoracic (n = 6) recurrence; three patients died without tumors of comorbidity. Among the six tumors recurring in extrathoracic sites, five (83%) harbored intratumoral (n = 4) or peritumoral (n = 1) blood vessel invasion. Both recurrence of disease and death from non-small-cell lung cancer were significantly (p = 0.0009) higher for tumors with blood vessel invasion. By univariate analysis, significant predictors of survival were tumor stage (T1 vs T2, p = 0.008), size (< or = 2.6 cm vs > 2.6 cm, p = 0.039), mitotic count (< or = 8 vs > 8 mitoses, p = 0.0007), and blood vessel invasion (absence vs presence, p = 0.0001). By multivariate analysis, however, only blood vessel invasion retained its level of prognostic significance (p = 0.006). Data demonstrate that peripheral, node-negative non-small-cell lung cancers have a low metastatic potential. Whenever anatomically feasible, wedge resection seems to be an appropriate method of primary treatment.


Diverse classes of T-cell lymphomas arise in T-lymphocyte-inductive epitheliomas of the mouse salivary gland. During the course of serial transplantations of polyomavirus-induced C3H-Bittner salivary gland epitheliomas in F1-hybrid mice, three tumor sublines were found which gave rise to T-cell lymphomas of host origin. The lymphomas resembled spontaneous AKR/J thymic lymphomas in their expression of lymphoid differentiation antigens, and they may represent sequential stages in the differentiation of immature T lymphocytes. We found no evidence that polyomavirus directly induced the lymphomas, rather, the lymphomagenic events paralleled those which occur in spontaneous AKR/J thymic lymphomas.


The combined EEG-intracerebral microdialysis technique: a new tool for neuropharmacological studies on freely behaving animals. In this study we combined EEG and intracerebral microdialysis techniques in freely behaving rats. Various drugs were delivered into the hippocampus and cerebral cortex by means of microdialysis and, simultaneously, the EEG activity of the dialyzed area was monitored. The microdialysis procedure itself, when artificial cerebrospinal fluid was perfused, did not change the normal hippocampal or cortical EEG pattern. Drug inclusions into the microdialysis fluid, however, caused marked changes in the electrical activity of the dialyzed sites. In this report we present the following examples: (1) the dose-dependent spike-provoking effect of NMDA in hippocampus, (2) the potentiation of this NMDA effect in hippocampus by dibutyryl cyclic AMP, and (3) the EEG depressant effect of high concentration of K+ in the cerebral cortex. The artificial cerebrospinal fluid and drug solutions were alternated in the microdialysis system with a 2-way valve placed outside the test chamber. As a consequence, the drugs were delivered into the brain without interrupting the ongoing behavior, including sleep, of the examined animals. This study shows that the combined EEG-intracerebral microdialysis technique is a useful tool, with many unique advantages, for in vivo neuropharmacological studies.


A simple, highly sensitive assay for measurement of digitonin during receptor solubilization. A simple and highly sensitive assay for measuring total digitonin in biological samples is described. The assay is based on the ability of digitonin to hemolyze red blood cells. The precision and reproducibility of the assay was excellent with intra- and inter-assay variabilities of less than 1% and 6%, respectively. The assay was used to evaluate several potential methods for removing digitonin from biological samples (digitonin extracts from guinea pig brain membranes). Dialysis and G-25 Sephadex chromatography were ineffective. However, protein and digitonin can be effectively separated by ammonium sulfate precipitation followed by dialysis. The kappa 1 opioid receptor survived these procedures with no change in affinity for [3H]U-69,593. In conclusion, the hemolytic assay for digitonin appears to provide a practical means for determining detergent concentrations during receptor purification and characterization and for evaluating potential methods for detergent removal. Although an in depth analysis of the assay was carried out only for digitonin, CHAPS and deoxycholate also caused 50% hemolysis at concentrations well below those commonly used for receptor solubilization and, therefore, the general assay procedures might have applicability for measurement of these and perhaps other detergents used in receptor solubilization as well.


Modeling of the quantal release at interneuronal synapses: analysis of permissible values of model moments. A theoretical study of effects of the different factors on fluctuation of post-synaptic potential (PSP) amplitudes was undertaken, using computation of regions of permissible values (RPV) of the ratio between the variance and the mean number of the quanta released (R1) and the ratio between the third moment and the variance (R2). The RPVs of these indexes for the binomial model were compared with regions determined for a number of models incorporating several factors. It has been shown that the involvement of temporal non-uniformity of transmitter release probability, decremental spreading of potentials along dendrites, and failure of spike propagation give the values of skewness index R2 less, compared to the binomial model. Simultaneously, a number of other factors, especially spatial non-uniformity of release probabilities in single release sites, would give amplitude histograms with high positive values of the index. The values of R1 and R2, calculated for 21 samples of sensorimotor EPSP amplitudes, were biased from RPV of these parameters constructed for the binomial model. The scattergram of R1 and R2 can be explained by the presence of two kinds of contacts which release quantum with different probabilities. The same was true for the beta-model based on the assumption that probabilities of quantal release are a sample of values of random variable that has beta-distribution. From analysis of the distribution of individual release probabilities, obtained from evaluation of beta-model parameters, is concluded that a greater part of boutons in the sensorimotor synapses release transmitter with very low probabilities, there being, however, a few boutons with probabilities close to 1.


Increased synthesis of extracellular spleen glycosaminoglycans in an experimental myeloproliferative syndrome. The changes occurring in the hematopoietic extracellular matrix in an experimental myeloproliferative syndrome were explored by comparing the glycosaminoglycan (GAG) composition of normal mouse spleens and spleens infected with myeloproliferative sarcoma virus (MPSV). Large quantities of hyaluronate and of sulfated GAGs accumulated in the extracellular matrix of infected spleens, as shown by histoimmunoassay and alcian blue staining, respectively. The splenic GAGs were either labeled with 35S-sulfate injected in vivo or unlabeled. The spleens were fractionated to separate hematopoietic cells from the stromal component containing extracellular matrix material and fibroblasts, and the GAGs were extracted from each fraction. Specific degradative treatments and electrophoresis indicated that sulfated GAGs were mostly chondroitin sulfate and heparan sulfate. Three hours after in vivo injection of 35S-sulfate, the amount of 35S-GAGs was increased approximately fivefold per mg stromal proteins. The bulk of these 35S-GAGs (70%) was recovered in the stromal fraction. The higher amount of sulfated GAGs in leukemic spleen was due both to the presence of more producer cells (infected fibroblasts and hematopoietic cells) and to a stimulation of GAG synthesis per cell, as evidenced 35S-labeling in in vitro experiments. Chondroitin sulfate was the main sulfated GAG present in the culture medium of both hematopoietic and fibroblastic cells and in the pericellular material released by trypsin from fibroblastic cells. High amounts of chondroitin sulfate, which has a possible role in the detachment of hematopoietic cells from the stromal cells, may favour the release of hematopoietic cells from the spleen into the peripheral blood. Heparan sulfate was produced by fibroblastic cells and it was principally present in their pericellular material. Considering the capacity of heparan sulfate to retain cytokines, as demonstrated by others in vitro, large amounts of heparan sulfate may result in the retention of large amounts of the cytokines, which production is enhanced in the infected spleen. This phenomenon may contribute to promote the hematopoietic stem cell proliferation characteristic of the MPSV-induced myeloproliferative disease.


Rearrangement and diversification of T-cell receptor delta genes in acute lymphoblastic leukemia. The current study was designed to determine the nucleotide sequence of two distinct T-cell-receptor delta chain (TCR delta) rearrangements which account for 95% of all rearranged alleles in common non-T, non-B lymphoid precursor acute lymphoblastic leukemia (LP-ALL). The results presented demonstrate that TCR delta rearrangements in LP-ALL are incomplete, immature, and involve V delta 2 to D delta 3 or D delta 2 to D delta 3 joints. These rearrangements are found in most cases of ALL. These results are consistent with the hypothesis that these leukemias originate in multipotent lymphoid precursor cells. The remarkable diversity of the rearrangements detected by polymerase chain reaction, cloning and sequencing demonstrates the clonal specificity and potential for detection of leukemic residual disease. However, in some cases the number of nucleotide differences may not be sufficient for the discrimination of leukemic and non-leukemic cells carrying V delta 2-(D)-D delta 3 rearrangements. A novel inversional rearrangement was demonstrated in one leukemia. This novel inversional rearrangement potentially increases the degree of diversity of the junctional region which encodes the antigen binding domain of TCR delta.


MKW, a novel hematopoietic antigen.

MKW, a novel hematopoietic antigen. A novel hematopoietic antigen was identified using a murine monoclonal antibody raised against KG-1 cells. This antigen, termed MKW, was also detected on the surface of the monocytic cell line U937, but not on the K562, ML1, or HL-60 cell lines. On normal hematopoietic cells, the antigen is expressed on the surface of monocytic and myelocytic cells and on a subpopulation of B-cells. During normal hematopoiesis, the surface expression of MKW is greatest and occurs very early on monocytic cells. Alternatively, in myeloid cells, surface expression occurs later and cell maturation is correlated with increased surface expression. When U937 cells are induced to differentiate, surface expression is transiently up-regulated. Surface expression of MKW, however, does not appear to be an activation antigen since activation of purified T- or B-cells failed to increase MKW on the cell surface. Leukemic blasts from 22 of 80 children (27%) with acute myeloblastic leukemia and from 29 of 225 children (13%) with acute lymphoblastic leukemia expressed MKW on the cell surface. Although surface expression of MKW was absent on T-cell lines, peripheral T-cells, and most B-cells, the antigen was identified in the cytoplasm of some B-cells, T-cells, and cell lines. Immunoprecipitation studies showed that MKW is a 52-kDa protein whether expressed on the cell surface or in the cytoplasm, and it appears to be nonglycosylated. Furthermore, studies with phosphatidylinositol-phospholipase C suggested that MKW is not attached to a glycolipid anchor. The biochemical characterization of MKW and its pattern of expression are distinct from any of the previously identified CD groups or published antigens. Since this unique antigen has prognostic significance in leukemia and appears to be associated with cell differentiation, its exact role in hematopoiesis should be investigated.


Age-related changes in neutrophil structure and function. The elderly suffer higher rates of morbidity and mortality from infectious disease than younger adults. Since neutrophils are the first line of defense against infection the vulnerability to infection of the elderly may be due, at least in part, to age-related changes in neutrophils (PMNs). Previous studies have suggested that there is an age-related increase in plasma membrane microviscosity in lymphocytes and neurons of the elderly. We have explored the hypothesis that there is a similar change in plasma membrane viscosity in the neutrophil and that this alteration in the neutrophil plasma membrane leads to diminished neutrophil function. When we studied plasma membrane viscosity of neutrophils by determining the fluorescence anisotropy of 1-(4-trimethylaminophenyl)-6-diphenyl-1,3,5-hexatriene labeled cells, we were surprised to find that plasma membrane viscosity is decreased in the neutrophils of the elderly as compared to young controls (microviscosity parameter, 1.33 +/- 0.07, in the elderly, n = 21, versus 1.62 +/- 0.06, in young controls, n = 19, P less than 0.004). As expected, stimulated (FMLP 0.1 microM) O2- generation by neutrophils from the elderly was significantly decreased compared with young controls (34 +/- 7% decrease, n = 6, P less than 0.04). Both resting and stimulated neutrophils demonstrated an age-related decline in adherence to a component of the extracellular matrix, denatured collagen (gelatin, P less than 0.04, n = 22 elderly subjects). In contrast, neutrophils from the elderly adhered to fibrinogen at least as well as neutrophils from young controls. Moreover, chemotaxis to activated complement components (in zymosan activated plasma) and FMLP did not change with increased age whether studied in the Boyden chamber (92 +/- 7% control, n = 14) or under agarose (90 +/- 13% control, n = 11). These studies suggest that an age-related decrease in plasma membrane viscosity is associated with a decrease in O2- production and adherence of neutrophils to components of the extracellular matrix. Thus, age-related alterations in neutrophil structure may result in diminished neutrophil function and increased susceptibility to infection with pyogenic bacteria.


[Use of DNA amplification to diagnose cytomegalovirus in HIV seropositive patients]. Cytomegalovirus (CMV) infection is common among HIV seropositive patients, being difficult to diagnose because it requires cell cultures not available in all hospitals. DNA amplification is being applied for diagnosis of infectious diseases with an increase in sensitivity and specificity with respect to previous laboratory methods. Polymerase chain reaction (PCR) has been used in comparison with culture isolation, early antigen detection to diagnose CMV infection in 22 HIV infected patients, that suffered from symptoms compatible with CMV infection at the present time, and in other 5 patients suffering from Kaposi sarcoma. PCR was done with primer for CMV IE genomic region. The amplified sequences were detected after hybridization with a gamma-P-32 labelled probe, followed by electrophoresis in a 5% polyacrylamide gel and autoradiography. The PCR allows to detect CMV genome in cases in which other tests are negatives, in blood as well as in urine, included those patients suffering only from febrile symptoms or with other associated pathogen. PCR is a sensitive method to detect CMV, although it does not establish the responsibility of CMV in HIV infected patients.


[Astrocytes are of vital significance for the central nervous system]. The tissue of the CNS (central nervous system) is composed of neurons and neuroglia. Whereas neurons develop an ability for the rapid transduction of specific signals, astrocytes develop an ability to modulate the extracellular neuronal environment, and in mature CNS tissue manifest a capacity for active uptake of amino acids and ions. Astrocytes can control extracellular volume by regulation of their own volume, and are intimately involved in the neuronal exchange of trophic substances and metabolites. Astrocytic processes extend to blood vessel walls, the brain surface, the ventricular wall, neuronal cell bodies and synapses. Astrocytes are abundantly supplied with membrane receptors for various neurotransmitters, coupled to such second messenger systems as cyclic AMP (adenosine monophosphate) or the phosphatidylinositol cycle. Activation of the receptors results in changes in oxidative metabolism, cell morphology, cell volume, and immunocompetence: and recent findings have shown the occurrence of receptor-mediated changes in amino acid uptake. Thus, by modulating the extracellular environment, astrocytes can simultaneously modulate the sensitivity and/or excitability of large numbers of neurons. In the article are presented recent research findings suggesting astroglial cells to be targets for neurotransmitters, and probably to be actively involved in higher cognitive functions. Advances in our knowledge of astroglial cell characteristics might improve our understanding of behavioural disturbances and diseases of the CNS.


[Perioperative prevention of thromboembolism with standard heparin and low molecular weight heparin, evaluation of postoperative hemorrhage. A double-blind, prospective, randomized and mono-center study]. From October 1987 through June 1988 594 patients admitted to the department of visceral surgery, were included in a prospective, randomized double-blind study dealing with postoperative thromboembolic complications. 5000 I.U. heparin were administered twice daily to one group, the other group received a single dose of low molecular heparin (3000 I.U. anti-Xa) daily. In each group more than 290 patients were included. Diagnostic screening was done using LCCT (Liquid Crystal Contact Thermography) and phlebography. 130 patients had to be excluded from the study. 66 patients because of contra-indication, 54 patients because of administrative failing and 10 patients were excluded by the surgeon himself. There was no significant difference between the two groups concerning thromboembolic complications. However analysis of the patients who were excluded from the study shows an increase of thromboembolic complications. Looking at cases of postoperative haemorrhage we found that there was no significant difference between both groups. Interestingly, even compared to the excluded group, there was no difference. In our study postoperative haemorrhagic complications did not depend on the method of prophylaxis but on the surgeon performing the operation. Should a patient have a contra-indication for administration of thromboembolic prophylaxis, he has to take a certain risk of thrombosis. The fact that prophylaxis was not initiated because of neglect or fear of haemorrhagic complications is not only unforgiveable, but dangerous as well.


Hydroxylapatite ossicular replacement prostheses: results in 157 consecutive cases. The use of hydroxylapatite for ossicular chain reconstruction is increasing. In this study, hearing results and extrusion rate for 157 consecutive patients receiving hydroxylapatite prostheses were evaluated. Results were compared to those of a control group of patients who had received either homograft bone or Plasti-Pore prostheses. Four (2.6%) cases of extrusion have occurred. Hearing success was defined as a postoperative puretone average air-bone gap of < or = 15 dB for incus prostheses and partial ossicular replacement prostheses (PORPs) or < or = 25 dB for incus-stapes prostheses and total ossicular reconstruction prostheses (TORPs). Overall success rate in the hydroxylapatite group was 51.4% for the 140 patients with postoperative data (mean follow-up, 11.5 months) and 46.7% for 90 patients who were followed for more than 6 months (mean follow-up, 16 months). PORP results were significantly poorer than those of the other prostheses. The success rate for the control group was 58.6% for 58 patients. The difference between hydroxylapatite and control group success rates appears to be due to the poorer results of the hydroxylapatite PORP.


Long-term effects of Silastic sheeting in the middle ear. Silastic sheeting is used to restore a mucosally lined middle ear space and to prevent mucosal adhesions between the medial surface of the tympanic membrane and the promontory after surgical procedures involving the removal of middle ear mucosa. To determine the long-term (1.2 to 21.2 years) effects of Silastic sheeting in the middle ear, six temporal bones from patients with permanent Silastic sheeting in the middle ear cavity after single-stage tympanoplasty were examined. In all six bones, no histologic evidence of foreign body reaction, rejection, or chronic inflammation in the middle ear surrounding the silicone sheeting was observed. Furthermore, the middle ear space was lined by normal-appearing, continuous middle ear mucosa. In four temporal bones, there was no evidence of significant submucosal fibrosis. In two bones, significant submucosal fibrosis was attributable to concurrent middle ear disease rather than to the presence of the silicone. It is concluded that Silastic sheeting in the middle ear after single-stage procedures may prevent adhesions between mucosal surfaces. Given eustachian tube function, Silastic promotes a mucosally lined, aerated middle ear cavity without apparent foreign body reaction, rejection, or chronic inflammatory response.


The effects of retinoic acid on the in vitro and in vivo growth of neuroblastoma cells. In large part, malignancy is the end result of aberrant cell growth and differentiation. Control of these processes is anticipated to result in a suppression of oncogenicity. Retinoic acid (RA), a derivative of vitamin A, has been shown to inhibit proliferation, induce cell differentiation and reverse the malignant phenotype of a variety of tumor cell types. In order to further characterize the antitumor potential of RA, this study examined the in vitro and in vivo effects of this retinoid on cell lines derived from human neuroblastoma (NB). The in vitro phase of this study tested the ability of various compounds to raise intracellular cyclic adenosine 3':5'-monophosphate (cAMP) levels and either alone or in combination with RA, to promote differentiation of two relatively RA-resistant cell lines. Direct activation of the synthetic enzyme adenylate cyclase by forskolin or cholera toxin increased intracellular cAMP levels over 10-fold after 1 hour of treatment, declining over the next 16 to 24 hours. After 5 days of continuous growth in the presence of these agents, cAMP levels remained elevated 2- to 7-fold above control values and were accompanied by a decrease in cell proliferation and an increase in cell differentiation. All these effects were exaggerated in the presence of phosphodiesterase inhibitors. Isoproterenol and epinephrine did not alter cAMP levels and had no discernible biological effects. RA promoted differentiation with little effect on cAMP levels. Combination treatment of cells with RA plus agents that raised cAMP levels resulted in greater degrees of differentiation than seen with single-agent treatment. From these data, it was concluded that: 1. the cAMP synthetic and degradative pathways are functional in the NB cell lines studied; 2. elevation of cAMP is a sufficient but not necessary condition for inhibiting proliferation and promoting differentiation in these cells; 3. elevation of intracellular cAMP potentiates the differentiation-inducing activity of RA; and 4. overcoming retinoid resistance in some tumor cell lines may be feasible by alterations in the cAMP system. This would be of particular value in treating tumors that have lost retinoid responsiveness. The in vivo phase of this study examined the effects of single-agent treatment using RA on the development and growth in nude mice of tumors derived from a NB cell line.(ABSTRACT TRUNCATED AT 400 WORDS)


[Cytomegalovirus infections of the gastrointestinal tract]. Histopathological findings in 8 cases of CMV infections of the gastrointestinal tract including 5 cases with AIDS are presented. The cytomegalic cells were irregularly distributed and were predominantly found in esophagus, small bowel and colon. Viral inclusions were detected in "stromal" cells and in endothelial cells, sometimes associated with lesions of the vascular wall. Cytomegalic smooth muscle cells and glandular epithelia were also observed. No correlation was found between the number of cytomegalic cells per mm2 of tissue and the inflammatory response. Monoclonal CMV antibodies reacted immunohistologically not only with cytomegalic cells but also with a few normally appearing cells. The in-situ-hybridization detected CMV-DNA also in cells which were negative for CMV antigens. Notwithstanding the new immunohistological techniques the searching for cytomegalic cells and their recognition still belong to the most important steps required for the diagnosis of CMV infection.


Inhibition of Sendai virus by various snake venom. Viperid, elapid and crotalid snake venoms were screened in vitro for antiviral activity against Sendai virus. The hemolysis of 10(8) human erythrocytes in 1 ml, caused by 70 HAU of Sendai virus, was abolished when the virions were pretreated with 10 ug of the viperid venom of Echis coloratus, and was considerably diminished when pretreated with 10 ug of the venom of Echis carinatus sochureki, the cobra venoms of Naja atra and Naja nigricollis nigricollis. These venoms did not affect the erythrocytes but inhibited the virions themselves irreversibly. All other examined snake venoms had low or no antiviral activity. There was no correlation between the proteolytic and the antiviral activity of the venoms.


Actions of thrombin and thrombin receptor peptide analogues in gastric and aortic smooth muscle: development of bioassays for structure-activity studies. We have examined the biological activities of thrombin and the thrombin-receptor-related polypeptides, S42FLLRNPNDKYEPF55(TRP42-55), S42FLLRNPND50(TRP42-50), and A42FLLRNPND50(A42-TRP42-50) as well as an arginine-containing basic peptide beginning with the SF motif (SFRGHITR), in rat aortic (RA) rings and in a gastric guinea pig longitudinal (LM) smooth muscle preparation. In the RA preparation, thrombin, as well as the three receptor-related peptides caused a relaxation in tissue that was precontracted with noradrenaline; the basic peptide, SFRGHITR, was inactive either as an agonist or as an antagonist to TRP42-55. In the LM bioassay, which unlike the RA preparation did not persistently desensitize in response to thrombin, all three receptor-related peptides, like thrombin, caused a prompt phasic reproducible contraction. The basic peptide, SFRGHITR, was inactive. In the LM assay, TRP42-55, TRP42-50 and A42-TRP42-55 all caused comparable contractile responses. We conclude that the gastric LM smooth muscle possesses a thrombin receptor and provides a convenient and reliable assay for the activities of thrombin receptor-related peptides. Our data also demonstrated that neither the C-terminal hirudin-related pentapeptide nor the N-terminal serine hydroxyl group are required for the biological activity of the thrombin receptor-derived peptide previously described (TRP42-55). Based on our findings we suggest that only a small portion of the N-terminal sequence of TRP42-55 may be required for thrombin-like biological activity.


Effect of PGE2 on interleukin-1 and superoxide release from primary-cultured human hepatic macrophages. In order to learn more about how human hepatic macrophages function, we analyzed the effect of exogenous PGE2 on the amounts of interleukin-1 (IL-1) and superoxide (O2-) released from primary-cultured human hepatic macrophages (HHM phi). When endogenous PGE2 production was blocked by indomethacin, exogenous PGE2 reduced IL-1 release from HHM phi in a dose-dependent manner, whereas it tended to increase O2- release from HHM phi. These results may suggest the probable contribution of PGE2 in regulating HHM phi mediator release in vivo.


Deoxyribonucleolytic activity of alpha- and beta-momorcharins. alpha- and beta-Momorcharins were purified by an improved procedure using the affinity Affi-gel Blue gel and the ion exchange Mono-S FPLC column. Both purified alpha- and beta-momorcharins possessed deoxyribonucleolytic activity. Under normal digestion conditions, they cleaved the supercoiled, double-stranded SV-40 DNA to produce nicked circular and linear DNAs. Prolonged incubation did not have any further effects. On the other hand, the linear DNAs, lambda, Ad-2 and T7 were not digested by alpha- nor beta-momorcharin. Thus, it appears that the conformation of the DNA may be the determining factor for the deoxyribonucleolytic activity of these momorcharins.


The effect of borage oil consumption on the composition of individual phospholipids in human platelets. The effect of supplementation with borage oil containing gamma-linolenic acid (GLA, 18:3n-6) on the levels and fatty acid compositions of individual human platelet phospholipids was evaluated. For this purpose, male volunteers were given an average daily intake of 5.23 g of GLA (as borage oil) for 42 days, after which the supplement was withdrawn for an additional 42-day period. No significant differences were found in the relative amounts of the choline phospholipids (PC), ethanolamine phospholipids (PE), phosphatidylserine (PS), phosphatidylinositol (PI), and sphingomyelin (SPH) at days 0, 22, 43, 64, and 85. However, marked differences were observed in the fatty acid compositions of all the phospholipids including a marked, and reversible, rise in the level of dihomo-gamma-linolenic acid (DGLA, 20:3n-6), without a significant elevation in arachidonic acid (AA, 20:4n-6) and decreases in n-3 polyunsaturated fatty acids. In the case of PC, a net rise in DGLA of 1.8 mol% was observed by day 22 (from 2.1 to 3.9 mol%). The DGLA/AA ratios at day 43 exhibited considerable variability across phospholipids with PC greater than PS greater than PE = PI; the PC, PE, PS, and PI accounted for 67.6, 16.7, 12.9, and 2.6%, respectively, of the total DGLA in platelet phospholipids. Interestingly, despite the lack of DGLA in SPH, this phospholipid exhibited a marked enrichment in nervonic acid (NA, 24:1n-9) from 16.2 to 24.7 mol% upon borage oil consumption. The observed alterations may represent biochemical strategies for adaptation to dietary fatty acid modifications and the regulation of platelet membrane functioning.


Derivatives of di-O-octanoylglycerol and mono-O-octylglycerol as modulators of protein kinase C and diacylglycerol kinase activities. Twelve analogs of 1,2-di-O-octanoylglycerol modified at C-3 and three quaternary N-alkyl-ammonium derivatives of glycerol were synthesized. The compounds were tested in vitro as potential modulators of the calcium activated, phospholipid dependent protein kinase C (PKC) and diacylglycerol (DAG) kinase activities in order to understand the molecular interactions of these enzymes with their natural activators, inhibitors, or substrates. PKC activity was assayed by measuring histone H1 phosphorylation, and the compounds synthesized were tested either in the presence (inhibitors) or in the absence (activators) of 1,2-di-O-octanoylglycerol analogs with the phosphatidylserine/Ca2+ mixture. DAG kinase activity was measured by the incorporation of phosphate into 1,2-di-O-oleoyl-sn-glycerol in the presence of the various analogs synthesized. In regard to PKC activity, the assays revealed that 1,2-di-O-octanoylglycerol analogs are inactive when modified at C-3 with groups which do not permit hydrogen bonding. Under our conditions, di-O-octanoylthioglycerol, which has been reported as inactive, was able to activate PKC in the presence of phosphatidylserine. It has been shown to give a synergistic activation with diacylglycerol and had no affinity for the phorbol ester receptor binding site, suggesting that O-octanoylthioglycerol interacts with the enzyme at a different site from the phorbol ester receptor binding site. PKC and DAG kinase activities are inhibited by N-alkyl-ammonium compounds (IC50 24 microM) only when either two 8-carbon alkyl or acyl chains are present at the 1- and 2-positions of the glycerol backbone.(ABSTRACT TRUNCATED AT 250 WORDS)


Reaction of dipyridamole with the hydroxyl radical. Dipyridamole [2,6-bis-diethanolamino-4,8-dipiperidinopyrimido-(5,4-d)pyri midine], a well known platelet aggregation inhibitor, shows powerful hydroxyl radical scavenging activity by inhibiting OH.-dependent salicylate and deoxyribose degradation. Steady-state competition kinetics experiments with deoxyribose were carried out to evaluate the second-order rate constant for the reaction between hydroxyl radical and dipyridamole. OH. radicals were generated either by a Fenton-type reaction or by X-ray irradiation of water solutions. A second-order rate constant k(Dipyridamole + OH.) of 1.72 +/- 0.11 X 10(10) M-1 s-1 and of 1.54 +/- 0.15 X 10(10) M-1 s-1 was measured by Fenton chemistry and by radiation chemistry, respectively. Mannitol was used as an internal standard for hydroxyl radicals in steady-state competition experiments with deoxyribose. A rate constant K(Mannitol + OH.) of 1.58 +/- 0.13 X 10(9) M-1 s-1 and 1.88 +/- 0.14 X 10(9) M-1 s-1 was measured in the Fenton model and in the water radiolysis system, respectively. Both these rate constants are in good agreement with the published data obtained by the "deoxyribose assay" and by pulse radiolysis.


Reversible ATP-dependent inactivation of adipose diacylglycerol acyltransferase. Diacylglycerol acyltransferase from rat adipose tissue is shown to be inactivated by 30 to 40% upon incubation with adenosine 5'-triphosphate (ATP) and Mg2+. The activity responsible for this inactivation is associated with the cytosolic fraction, specific for ATP, prevented when ATP is substituted by beta,gamma-methylene-ATP, and partially blocked by 1 mM ethylenediaminetetraacetate or 40 mM NaF, but not by inhibitors of adenosine 3',5'-cyclic-monophosphate (cAMP)-dependent protein kinase and/or protein kinase C (PKC). The cytosolic activity cannot be mimicked by (cAMP)-protein kinase nor by PKC. Inactivated diacylglycerol acyltransferase from ATP/cytosol-treated microsomes can be reactivated by incubation with partially purified protein phosphate from rat liver, and can be inactivated again by further addition of ATP in the presence of cytosol. The results suggest the existence in adipose tissue of a protein kinase other than cAMP-protein kinase or PKC, which may be involved in the regulation of triacylglycerol synthesis.


Reversible or irreversible modification of [3H]PAF binding on rabbit platelet membranes differentiates various PAF receptor antagonists. [3H]Platelet-activating factor (PAF) binding to rabbit platelet membranes was examined before and after 20 min preincubation at 25 degrees C in the presence of PAF, lysoPAF, or of five different PAF receptor antagonists (L 652731, BN 52021, WEB 2086, BN 52111 and BN 52115). When platelet membranes were not washed after preincubation with PAF or PAF antagonists, no significant specific binding of [3H]PAF was observed, which suggests full occupancy of the binding sites. When membranes were extensively washed, full recovery of specific [3H]PAF binding was attained with L 652731 and partial recoveries (60%, 55% and 30%) were reached with BN 52021, WEB 2086 and PAF, respectively; no recovery was seen with the dioxolanes BN 52111 and BN 52115. Scatchard analysis of the binding data indicated that no significant change in the dissociation constant (Kd) and maximum number of binding sites (Bmax) occurred after preincubation of platelet membrane with L 652731, whereas a reduction of Bmax was observed when PAF and BN 52021 were measured. When platelet membranes were preincubated with WEB 2086, Bmax and Kd significantly increased. The data suggest differing binding properties for PAF and the PAF antagonists. Some of the PAF antagonists may tightly bind to the PAF receptor site(s) and/or irreversibly modify or downregulate PAF recognition sites. Our results also suggest that the interaction of PAF receptor antagonists with PAF receptor can be divided into at least two components, namely a reversible component and an irreversible one.


Arachidonic acid biosynthesis in non-stimulated and adrenocorticotropin-stimulated Sertoli and Leydig cells. The biosynthesis of arachidonic acid in Sertoli and Leydig cells isolated from the testes of mature rats has been investigated. Both types of cells incorporated [2-14C]eicosatrienoic acid from the incubation medium and transformed it into arachidonic acid. The administration of adrenocorticotropin (ACTH) to the rats decreased the delta 5 desaturating activity in the isolated testicular cells, while ACTH produced no changes in the uptake of the substrate. Similar results were obtained when ACTH was added to the incubation medium of cells isolated from non-hormone treated rats. The total fatty acid composition of the Sertoli cells isolated from ACTH-treated rats showed a significant increase in the relative percentage of 18:2n-6 and a decrease in the C20 and C22 polyenes. This may indicate that ACTH exerts an inhibitory effect on delta 6, delta 5 and delta 4 desaturase activities. Addition of corticosterone to the incubation medium also produced a significant decrease in arachidonic acid biosynthesis. Because ACTH is known to stimulate the release of corticosterone in vivo, both hormones may act cumulatively in the regulation of arachidonic acid metabolism in Sertoli and Leydig cells.


Segmental mean transit times of 99mtechnetium within central vascular space in liver cirrhosis. Mean transit time (MTT) through a given vascular space is closely related to the effective blood volume in this compartment. Central vascular blood volume in liver cirrhosis is believed to be reduced, but more precise data on the location of the underfilled vascular area are lacking. 99mTechnetium first-pass angiography was performed in 15 cirrhotic patients and in 10 age-matched normals. The method of segmental analysis of MTT was validated by performing an analog study in a plastic tubing/chamber system. The mean tracer sojourn in the central circulation was described in cirrhotic patients (10.25 +/- 2.17 s vs 12.92 +/- 2.88 s; p less than 0.05); however, this finding was not observed beyond cardiopulmonary circulation (MTT between right and left heart chambers). Segmental comparative analysis between cirrhotics and normals revealed significant MTT differences in two vascular subcompartments, i.e. right chamber-pulmonary artery, and within the lung vascular bed. Analysis of time activity lung curves in patients with cirrhosis disclosed a shorter time to peak and more rapid washout of the tracer from this area, without any change in curve symmetry as compared to normals. Ascites had no apparent impact on MTT rate, and cirrhotics with most advanced disease (grade C Child-Pugh) had longer MTT through the cardiopulmonary circulation as compared to combined groups A & B (7.32 +/- 0.13 s vs 6.03 +/- 1.23 s; p less than 0.05). Our data provide further evidence for contraction of the cardiopulmonary vascular space in liver cirrhosis.


Enhanced tumor necrosis factor alpha in coronavirus but not in paracetamol-induced acute hepatic necrosis in mice. Previous reports have demonstrated that tumor necrosis factor alpha (TNF-alpha) plays an important role in the pathogenesis of fulminant hepatic necrosis. The purpose of this experimental study was to measure TNF-alpha blood activity in paracetamol-induced liver necrosis and in coronavirus (MHV3)-induced fulminant hepatitis in mice. No elevation of TNF-alpha activity was found in hepatic failure complicating paracetamol poisoning. In contrast, TNF-alpha activity significantly increased in response to MHV3, reaching 16.3 +/- 5.5 U/ml from 24 h post infection (P less than 0.01). This augmentation was observed even though the virus was not detectable in the liver. Serum alanine aminotransferase levels were low and no histological lesion was observed. In conclusion, our study further supports the implication of TNF-alpha in virus-induced hepatitis failure and confirms that paracetamol poisoning does not cause increased TNF-alpha activity in the circulation.


Quantitation of treatment volumes from CT and MRI in high-grade gliomas: implications for radiotherapy. Long-term survival of patients with high-grade gliomas remains extremely poor. The main reason for such an outcome is local failure, or recurrence, after surgery and/or radiotherapy. Higher doses of radiation may result in decreased local failure rates provided that the location (and extent) of gross tumor and microscopic disease can be defined accurately. The abnormalities appearing in images from diagnostic modalities, such as CT and MRI, are being used as a starting point and as a guide for the clinical definition of tumor and its extensions. However, some recent studies on two-dimensional specimens, correlating histopathological findings to CT and MRI images, showed that the resulting definition of tumor cell extensions was unsatisfactory, different, and in need of ample margins. We carried out a retrospective analysis to compare the target volumes that would have been defined by CT, T2-weighted MRI, and T1-weighted postgadolinium MRI images of the same individual and to explore the implications of the resulting volume definitions for radiotherapy. The results of our limited study, based on the margins used, indicate that the CT-defined target volume is consistently larger than that from either of the two MRI modalities and suggest that noncoplanar approaches for its treatment and other local approaches for tumor boost should be considered. We conclude that until more definitive histopathological guidelines correlated to image features have been formulated and agreed upon, one should try to make full use of all available diagnostic information in order to minimize the possibility of geographical miss of target extensions.


Ergogenic and ergolytic substances.

Ergogenic and ergolytic substances. Genetic endowment and proper training are the major factors contributing to athletic success in endurance and ultraendurance events. Proper nutrition, primarily adequate carbohydrate and fluid, prior to and during the event is also critical. Endurance athletes often utilize other nutritional substances or practices, often referred to as ergogenics, in attempts to obtain a competitive edge by enhancing energy utilization and delaying the onset of fatigue. Numerous nutritional ergogenics have been used in attempts to enhance endurance performance, but with several exceptions most have been shown to be ineffective, including bee pollen, L-carnitine, CoQ10, inosine, amino acids, alkaline salts, and vitamin E at sea level. Research findings are equivocal relative to the ergogenicity of caffeine, phosphate salts, and vitamin E at altitude. Loss of excess body fat, a nutritional practice, may be an effective ergogenic. Conversely, some agents such as alcohol may impair performance, an ergolytic effect. Additional research is necessary to support the efficacy of several nutritional ergogenics to enhance prolonged endurance performance, such as caffeine, phosphates, specific amino acids, and various commercial products. Such research should involve exercise tasks comparable in intensity and duration to that experienced in the marathon and similar endurance events.


[Various ecological problems related to mining and processing of serpentine. Evaluation of non-occupational exposure of the population of Nasławice to fibrous mineral dust]. Non-occupational exposure of the population living in the vicinity of the serpentine mining and processing mill in Nasławice was assessed. The evaluation was based on the phase analysis and determination of respirable mineral fibres content in the samples of dust fall and soil in the fields nearby the mine, as well as on the in-door and out-door measurements of airborne fibres concentration. All soil samples contained antigorite--a mineral the structure of which is close to that of chrysotile asbestos add exhibiting high biological aggressiveness. The respirable mineral fibres content in the dust fall-out and in the soil ranged from 98,000 to 480,000 per 1 mg and from 48,000 to 122,000 per 1 mg, respectively, whereas the airborne concentrations were from 2 to 1540 fibres/l (outdoor) and from 4 to 7 fibres/l (indoor). The fall of dust in the years 1989-1990, recorded at all measuring points, exceeded 200,000 kg/km2 yearly (admissible value). The airborne concentrations of respirable mineral fibres were also higher than the admissible value (1 fibre/l of the air). The results obtained indicate that the exposure of the population in Nasławice to mineral fibrous dusts has significantly exceeded to maximum admissible concentrations established for non-occupational exposure.


[Etiological factors of deep vein thromboses in the limbs of Black African subjects]. Deep thrombosis of limbs are unknown in Africa South of the Sahara. Looking for their etiological factors, the authors reviewed 82 cases admitted with an undisputable diagnosis of thrombosis. They underline the coming in of the disease which appears to strike two targets populations female in strong genital activity and males between 40 and 60 years of age. The authors are of opinion that etiological factors are similar to those described in the literature but they underline some peculiarities. Anemia, mainly because of iron deficiency (30.5 p.c.) gyneco-obstetrical context with oral contraception (26.8 p.c.) dysmetabolism (19.5 p.c.) heredity (15 p.c.) and infections (14.5 p.c.) are on the top of etiological factors. Then we have congestive cardiopathies (9.7 p.c.) digestive lesions (6.1 p.c.) and neoplasiae, hemoglobinopathies, quite frequent in the region as well as surgical context without preventive anticoagulants (7.3 p.c.) do not seen to play a significant role: they start again the discussion about the natural protection of Black African against thrombo-embolic diseases. Finally, they point out the interest of antithrombine III and proteins C and S tests in any known causal factor.


[Asbestos substitutes and their biological effects. 2. Synthetic amphiboles--their physico-chemical characteristics]. Metal content in the chemical structure of asbestos and man-made mineral fibres can affect their carcinogenic properties. As the chemical composition (metal content) of man-made silicate substitutes for asbestos can be varied almost at will in the process of their manufacture, the search for potentially least carcinogenic silicates appears to be of utmost importance. This paper presents diffractometric characteristics, dimensional analysis and morphology data for 4 synthetic amphibole fibres with chemical compositions differing from that of natural crocidolite amphibole. Those included the following synthetic amphiboles: Na2Mg6Ge8O22(OH)2; Na2Ni6Si8O22(OH)2; Na2Mg6Si8O22(OH)2; Na2Co6Si8O22(OH)2. The studied amphiboles differed in fibre length and diameter. The magnesium amphibole contained the longest (6.03 microns) fibres, and the nickel amphibole contained the shortest (2.7 microns) fibres, resembling those of crocidolite. The highest content (54.7%) of respirable fibres was found in the magnesium amphibole, and the lowest (15.9%) in the natural crocidolite. The authors suggest that the detected differences in the physical and chemical characteristics of the synthetic amphiboles may affect their biological properties.


[Prevalence and genetic profile of alpha-thalassemia in the newborn in Ivory Coast]. The authors report 525 cases of alpha-thalassemia tracked from samples of cord blood proceeded from 12,709 new-borns. With a frequency of 4.13% alpha-thalassemia was frequently in studied population. The lack of symptomatical shapes (Hemoglobin H disease and hydrops foetalis) agree the present theory about the genetic of Black African alpha-thalassemia.


[Asbestos substitutes and their biological effects. 3. Carcinogenic effects of synthetic amphiboles in animal experiments]. This work presents the results of the test performed on rats to evaluate the carcinogenic effect of 4 synthetic amphiboles compared to that of the natural amphibole--crocidolite. The dose of the magnesium amphibole (Na2Mg6Si8(OH)2) administered to the animals contained 240 x 10(6) respirable fibres; the corresponding value for the nickel amphibole (Na2Ni6Si8O22(OH)2) was 339 x 10(6), for the cobalt amphibole (Na2Co6Si8O22(OH)2)--1000 x 16(6) for the geranium amphibole (Na2Mg6Ge8(OH)2)--250 x 10(6), and of the natural crocidolite amphibole (Na2Fe2Fe3Si8O22(OH)2) x 380 x 10(6) respirable fibres. The control animals (rats) received physiological NaCl solution. The number of peritoneal mesotheliomas following single intraperitoneal administration of 20 mg of the dust was adapted to be the measure of the carcinogenic activity of the dust. 3 synthetic (magnesium, cobalt and nickel) amphiboles and crocidolite caused development of malignant peritoneal mesothelioma in 11.1% to 71% rats. The results show that there is a relationship between the chemical composition of the synthetic amphiboles and their carcinogenic effect. Out of 4 investigated synthetic amphiboles, the magnesium amphibole, which contained magnesium and silicon, displayed most severe carcinogenic effect. The synthetic amphiboles containing either silicon and cobalt or silicon and nickel displayed 8.3 and 6.2 times weaker ability to induce peritoneal mesothelioma.


The delta-endotoxin protein family displays a hydrophobic motif that might be implicated in toxicity. A computer-based analysis of hydropathy and surface probability of representative members of each class of the Cry family of proteins was performed. A highly conserved hydrophobic motif within the previously described block, D2, is present not only in lepidopteran toxin genes but also in toxins active against diptera and coleoptera. An interesting feature of this hydrophobic motif is the presence of an aspartic residue (highly hydrophilic) in its middle part. Comparison with the amino acid sequence from diphtheria toxin showed that it also contains a hydrophobic motif similar to the one present in the Bacillus thuringiensis toxins. It also contains an aspartic residue in the middle part and some speculations are presented on the function of this specific region with regard to the toxic mechanism of action.


[Hemoglobin O Arab in Ivory Coast and western Africa]. The authors report 44 cases of hemoglobin O Arab share out in 3 phenotypes (A O Arab, C O Arab and S O Arab). The study of this abnormal hemoglobin has allowed the following conclusions: The Hb O Arab is a rare mutant of hemoglobin. The heterozygote form A O Arab and the association Hb C--Hb O Arab do not present any clinical and hematological manifestations. The associations Hb S--Hb O Arab brings about a serious hemoglobinopathy which has clinical and hematological features like the sickle-cell disease (SSFA2).


Variation in length and sequence of porin (ompP2) alleles of non-capsulate Haemophilus influenzae. Length variations of Haemophilus influenzae outer membrane porin protein P2 were found at the DNA and protein levels, notably in non-capsulate strains. Protein length, measured by SDS-polyacrylamide gel electrophoresis, was found to correlate with the length of the gene, measured by polymerase chain reaction amplification, and ranged from 35-42 kDa and 970-1090 nucleotides, respectively. This represents a length variation of some 15%. The genetic location of these variations was studied by restriction enzyme mapping 10 of the non-capsulate strains revealing further polymorphisms at the DNA level. All 10 strains were distinct and differed from a type b strain. The conservation and assortment of the different restriction sites in the alleles is discussed in relation to the very great diversity previously described for this protein and of the whole genome itself in non-capsulate strains. The roles of selection, horizontal gene transfer, and transformation in generating this diversity are discussed.


[Muscular metastasis disclosing a hepatocellular carcinoma in an African]. The authors notify a skeletal muscular metastasis case hepato-cellular carcinoma found in Black African at a decompensation ictero-ascetic stage. Any observation of muscular metastasis of a hepato-cellular carcinoma has been written in the document.


Molecular cloning and characterization of two lincomycin-resistance genes, lmrA and lmrB, from Streptomyces lincolnensis 78-11. Two different lincomycin-resistance determinants (lmrA and lmrB) from Streptomyces lincolnensis 78-11 were cloned in Streptomyces lividans 66 TK23. The gene lmrA was localized on a 2.16 kb fragment, the determined nucleotide sequence of which encoded a single open reading frame 1446 bp long. Analysis of the deduced amino acid sequence suggested the presence of 12 membrane-spanning domains and showed significant similarities to the methylenomycin-resistance protein (Mmr) from Streptomyces coelicolor, the QacA protein from Staphylococcus aureus, and several tetracycline-resistance proteins from both Gram-positive and Gram-negative bacteria, as well as to some sugar-transport proteins from Escherichia coli. The lmrB gene was actively expressed from a 2.7 kb fragment. An open reading frame of 837 bp could be localized which encoded a protein that was significantly similar to 23S rRNA adenine(2058)-N-methyltransferases conferring macrolide-lincosamide-streptogramin resistance. LmrB also had putative rRNA methyltransferase activity since lincomycin resistance of ribosomes was induced in lmrB-containing strains. Surprisingly, both enzymes, LmrA and LmrB, had a substrate specificity restricted to lincomycin and did not cause resistance to other lincosamides such as celesticetin and clindamycin, or to macrolides.


Activation of a cryptic streptomycin-resistance gene in the Bacteroides erm transposon, Tn4551. Bacteroides compound transposons encoding erm resistance are highly homologous but previous studies have shown some divergence of Tn4551. Results presented here describe a novel Tn4551 streptomycin-resistance gene, aadS, that was phenotypically silent in wild-type Bacteroides. However, aadS expression could be activated by a trans-acting chromosomal mutation. The aadS-encoded peptide displayed significant homology to Gram-positive streptomycin-dependent adenyltransferases, and enzymatic analysis confirmed the production of this activity. Examination of the nucleotide sequence showed that 200 bp upstream of aadS, the DNA base composition changed abruptly from 31% G+C to 48% G+C. These two regions were demarcated by a DNA sequence with homology to the recombination hot spots reported for Tn21 and the Bacteroides ermFU gene and to sequences at the ends of the chromosomal Bacteroides conjugal element, XBU4422.


The lactose operon-controlling elements: a complex paradigm. The lactose-controlling elements have been considered to be the simple paradigm of a cis-acting genetic regulatory system, containing a promoter whose activity is modulated by an operator and a catabolite gene activator protein (CAP)-binding site. The reality is considerably more complex. We now know that transcription is negatively regulated as a result of the repressor binding to three binding sites: the operator, a secondary repressor-binding site within the lacZ gene and a tertiary repressor-binding site upstream near lacI. In addition to the promoter, the lac-controlling elements contain five promoter-like elements. The physiological role, if any, of these promoter-like elements is not clear, although three of them can be activated by single base pair changes to give high levels of in vivo expression. Finally, the positive activator protein CAP has been found to bind to a secondary site which is coincident with the operator. No role has been identified for this secondary CAP-DNA complex.


A new aspect of transcriptional control of the Escherichia coli crp gene: positive autoregulation. Transcription of the Escherichia coli crp gene is negatively regulated by CRP-cAMP that binds to a specific site located downstream of the crp promoter. A second binding site for CRP-cAMP (CRP site II) exists upstream of the crp promoter. Using an in vitro transcription assay, we have demonstrated that CRP-cAMP activates transcription of crp in certain conditions. A promoter which carries an altered CRP-binding site II is no longer activated by CRP-cAMP, indicating that CRP site II mediates the activation of crp transcription. The concentrations of cAMP that are required for positive autoregulation are higher than those for negative autoregulation. Evidence for positive and negative autoregulation in vivo is presented by a quantitative S1 nuclease analysis.


Plasma lipid levels and platelet and neutrophil function in patients with vascular disease following fish oil and olive oil supplementation. This double-blind study was designed to examine and compare the effects of supplementing the existing diet with fish oil or olive oil on lipids and cell function in patients with peripheral vascular disease. Thirty-two patients with symptomatic and angiographically demonstrated peripheral vascular disease were screened, matched, and randomly allocated to take either 15 g/d fish oil or olive oil for 4 weeks. Fish oil reduced serum triglyceride levels by 26%, but increased total cholesterol levels due to a significant increase in both low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein-2 cholesterol (HDL2-C). There was a nonsignificant decrease in HDL3-C levels. Olive oil reduced total cholesterol levels, accountable to a significantly decrease in LDL-C levels. Serum thromboxane B2 (TXB2) levels remained unchanged following fish oil, but were significantly increased by olive oil. Urinary excretion of TXB2 and 6-keto-PGF1 alpha was unaffected by either oil supplement. Platelet aggregation, which was measured in platelet-rich plasma in response to two doses of collagen or platelet-activating factor (PAF), was significantly reduced after fish oil, but was increased by olive oil. Following fish oil, there was a significant increase in eicosapentaenoic acid (EPA, 20:5) and docosahexaenoic acid (DHA, 22:6) levels and a decrease in arachidonic acid content of platelet phospholipids. The platelet fatty acid composition after olive oil was unchanged. Fish oil decreased neutrophil leukotriene B4 (LTB4) generation following calcium ionophore stimulation by 33%, while leukotriene B5 levels increased significantly. Neutrophil PAF production and plasma lyso-PAF were unaffected by either oil.(ABSTRACT TRUNCATED AT 250 WORDS)


Dexamethasone increases apolipoprotein A-I concentrations in medium and apolipoprotein A-I mRNA abundance from Hep G2 cells. Glucocorticoid hormones increase high-density lipoprotein (HDL) levels in vivo. However, there is little known about the mechanism by which glucocorticoids alter HDL metabolism. Hep G2 cells were incubated with dexamethasone to determine the effect of glucocorticoids on apolipoprotein (apo) A-I secretion. Dexamethasone increased apo A-I concentration in a dose-dependent fashion. After 24 hours, 5.5 x 10(-5) mol/L dexamethasone increased apo A-I accumulation in culture medium by 54%. Detectable increases in apo A-I concentration were noted in medium by 5 hours of incubation and persisted up to 48 hours. Cellular apo A-I mRNA concentration increased by 28% after incubation with dexamethasone for 24 hours. The increase in apo A-I mRNA concentration was detectable within 3 hours after incubation with dexamethasone. In contrast, incubation with dexamethasone decreased apo B concentration by 43% in culture medium, but it had no effect on cellular apo B mRNA concentrations. Dexamethasone had little effect on cholesterol and triglyceride accumulation in the medium. Incubation with albumin alone did not affect apo A-I concentration, but it decreased apo B concentration by 30% in the medium. Incubation with albumin and dexamethasone had no effect on apo A-I concentration in medium and had no additive effect on apo B concentration. These data suggest dexamethasone increases secretion of apo A-I by Hep G2 cells by increasing mRNA levels.