Myeloperoxidase is a primary response gene in HL60 cells, directly regulated during hematopoietic differentiation

The expression of myeloperoxidase was studied in three human myeloid leukemic cell lines. The myeloperoxidase transcript was strongly expressed in promyelocytic HL 60 cells, whereas much lower levels were detected in immature monocytic U 937 cells. Phorbol-12-myristate-13-acetate induction resulted in inhibition of myeloperoxidase expression within 24 hrs. This regulatory event could not be blocked by cycloheximide. Furthermore, cycloheximide did not superinduce myeloperoxidase mRNA levels in KG 1, HL 60 and U 937 cells, arguing against the existence of a negative gene regulator for myeloperoxidase. Therefore, the myeloperoxidase gene can be classified as a primary response gene.

Interactions of myosin subfragment 1 isozymes with G-actin

The polymerization of G-actin by myosin subfragment 1 (S-1) isozymes, S-1(A1) and S-1(A2), and their proteolytically cleaved forms was studied by light-scattering, fluorescence, and analytical ultracentrifugation techniques. As reported previously, S-1(A1) polymerized G-actin rapidly while S-1(A2) could hardly promote the assembly reaction (Chaussepied & Kasprzak, 1989a; Chen and Reisler, 1990). This difference between the isozymes of S-1 was traced to the very poor, if any, ability of G-actin-S-1(A2) complexes to nucleate the assembly of actin filaments. The formation of G-actin-S-1(A2) complexes was verified in sedimentation velocity experiments and by fluorescence measurements using pyrene-labeled actin. The G-actin-S-1(A2) complexes supported the growth of actin filaments and accelerated the polymerization of actin in solutions seeded with MgCl2-, KCl-, and S-1(A1)-generated nuclei. The growth rates of actin-S-1(A2) filaments were markedly slower than those for actin-S-1(A1) filaments. Proteolytic cleavage of S-1 isozymes at the 50/20-kDa junction of the heavy chain greatly decreased their binding to G-actin and thus inhibited the polymerization of actin by S-1(A1). These results are discussed in the context of G-actin-S-1 interactions.

Prognostic factors in alcoholic liver disease. VA Cooperative Study Group

Two hundred eighty-one alcoholic patients were prospectively evaluated by clinical, biochemical, and histologic parameters during a 4-yr period to assess their prognosis. They were stratified into four categories of injury: 1) fatty liver (26 patients), 2) acute alcoholic hepatitis (106), 3) cirrhosis (39), and 4) cirrhosis with superimposed alcoholic hepatitis (111). The rate of survival and variables correlating with survival varied according to the group. At 48 months, 70% of the patients with fatty liver were alive, 58% in the alcoholic hepatitis group, 49% in cirrhosis, and 35% in alcoholic hepatitis superimposed upon cirrhosis. Within group one, deaths were due to causes unrelated to liver disease. In the alcoholic hepatitis group, factors significantly correlating with survival were ascites, alanine amino-transferase levels, grams of alcohol consumed, continuation of alcohol intake, and clinical severity of disease. Survival in patients of group three correlated significantly with prothrombin time and histologic severity score. Patients with combined cirrhosis and alcoholic hepatitis exhibited the worst prognosis, with the most significant predictors of survival being age, grams of alcohol consumed, the ratio of serum aminotransferases (AST:ALT) and the histologic and clinical severity of the disease. Although a different pattern of correlates was observed for each pathologic level of injury, knowledge of the various correlates aids in prognostic assessment.

Autoregulation of brain blood flow during hypotension and hypertension in infant lambs

To determine the limits of aortic blood pressure in infant lambs for autoregulation of global and regional brain blood flow, we studied 10 unsedated lambs during hypotension and 10 unsedated lambs during hypertension. In lambs 6 to 13 d old, we produced graded changes in aortic blood pressure by inflating a balloon occluder placed around either the inferior vena cava or the descending aorta. Using radiolabeled microspheres, we measured global and regional brain blood flow at the baseline, and then with each graded change in aortic blood pressure. In an additional step, we administered atropine to determine if its antimuscarinic properties alter the fall in brain blood flow with severe hypotension, or alter the rise in brain blood flow with severe hypertension. We concluded that in the unsedated infant lamb, global brain blood flow remains stable between mean aortic blood pressures of 6.0 to 10.0 kPa (45 to 82 torr), a range from approximately 38% below to 12% above normal mean aortic blood pressure. We noted that this autoregulatory range is essentially unchanged from that described for the fetal lamb at 80% of term gestation--even though the mean aortic blood pressure rises during this period of maturation by more than 2.7 kPa (20 torr). We found that the lower limit of autoregulation varies among the different brain regions and is lowest in the thalamus, pons, and medulla. We saw little variation of the upper limit among the brain regions. Finally, we determined that atropine does not alter brain blood flow during severe hypotension or severe hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of a complete immunoglobulin heavy-chain variable region germ-line gene of rainbow trout

A germ-line heavy-chain variable region (VH) gene (RTVH431) has been isolated from a rainbow trout (Salmo gairdneri) and characterized by complete nucleotide sequencing. It is characteristic of VH, as shown by the conserved octamer and TATA motif in the 5' region, the heptamernonamer recombination signal sequence in the 3' region, and the 18-amino-acid-long hydrophobic leader interrupted by an intron. The 98-amino-acid-long VH coding region has 50-70% nucleotide sequence homology and 40-60% amino acid sequence homology with VHS of various vertebrate species. We have also found unique or species-specific amino acid residues in the VHS of rainbow trout, amphibia (Xenopus), reptile (Caiman), and shark (Heterodontus) in our sequence analyses. The RTVH431 has an unusual amino acid in the conserved 34th position in complementarity-determining region 1 of VH. Southern hybridization results suggest the presence of a large gene family related to RTVH431 in the trout genome. The complex evolution of antibody V genes is discussed.

Metabolic stereoisomeric inversion of 2-arylpropionic acids. On the mechanism of ibuprofen epimerization in rats

Kinetic and mechanistic studies are described for the metabolic stereoisomeric inversion of R-ibuprofen in rats. After oral administration of R-ibuprofen to rats, the plasma levels and enantiomeric compositions of ibuprofen and its major metabolite were monitored. Although individual animals exhibited great variations in metabolic rates, the concentration ratios of the S- and R-enantiomers of ibuprofen and also its metabolite remained roughly unchanged within 90 min. Even though it is generally believed that this bioconversion is strictly stereospecific in nature, chromatographic analysis revealed that S-ibuprofen also underwent metabolic inversion, however, at a much slower rate, than its R counterpart. The inversion mechanism was assessed by monitoring the loss of labeled deuterium from specifically deuterated ibuprofen. No significant isotope effect was observed for the metabolism of these deuterated derivatives. One deuterium atom was lost in the S-ibuprofen resulted from R-[2-2H]ibuprofen metabolism, whereas all the three deuterium atoms were retained when R-[3,3,3-2H3]ibuprofen was used as the substrate. These results reinforce the proposed mechanism that the inversion proceeds via a thioester carbanion intermediate. The pKa of the alpha-methine proton of ibuprofen N-acetylcysteamine thioester was shown to be 10.34 +/- 0.06, which excludes the possibility that ibuprofen may undergo inversion through the nonenzymatic isomerization of its acyl thioester.

Reversed phase high performance liquid chromatography of glycopeptides

A practical procedure for isolating and purifying glycopeptides is described, viz. enzymatic hydrolysis-gel permeation chromatography-ion exchange chromatography-reversed phase HPLC. Using this procedure 28 glycopeptides from hen ovalbumin have been isolated some of which hitherto have not been identified. Water was a suitable mobile phase for preparing pure glycopeptides, and control of column temperature was important for good separations and reproducible retention times. Structural confirmation was by fast atom bombardment mass spectrometry.

[Effect of dexamethasone on the levels of plasma beta-endorphin-like-immunoreactivity in intestinal ischemia shock in the dog]

This paper observed the effect of Dexamethasone (Dex) on the levels of plasma Beta-endorphin-like-immunoreactivity (ir-beta-EP) and its correlation with hemodynamics during the shock. Ten adult mongrel dogs were randomized into two groups. Intestinal shock was created by occluding both superior mesenteric artery and vein in the two groups. After two hours of occlusion, the dogs in treated group were given Dex (5 mg/kg) and the dogs in control group were given normal saline. The intestinal vascular obstruction was released four hours later. It was shown that plasma levels of ir-beta-EP in control group were increased significantly during the shock and correlated significantly with deteriorated hemodynamics. In Dex treated group, the levels of plasma ir-beta-EP and ACTH were significantly lower than that in control group, hemodynamics were improved, and the survival times were much longer. Our results suggest that endogenous opiate beta-EP is involved in the cardiovascular pathophysiology of intestinal shock, and the beneficial effects of steroids (Dex) in the treatment of shock are correlated with its suppressing endogenous beta-EP secretion and release.

[The tendencies of research on Chinese materia medica in Japan--establishment of morbid models in animals and their application to research on Chinese materia medica]

This paper presents a survey of some pathologic models on animals established to satisfy the needs of research on Chinese materia medica in Japan over the last several years, e.g., model of blood-stasis syndrome, model of "taiyang" syndrome, model of spleen deficiency syndrome, speeded aging model and two related models, i.e. chronic renal insufficiency and bronchitis. All these models can be used for reference in the experimental research on Chinese materia medica.

Elevated bone aluminum and suppressed parathyroid hormone levels in hypercalcemic dialysis patients

We studied 21 dialysis patients who became hypercalcemic without vitamin D or calcium therapy and compared them to 28 dialysis patients who were not hypercalcemic. In the hypercalcemic group, the mean ionized-calcium level was elevated compared to normal subjects (5.4 +/- 0.4 vs. 4.9 +/- 0.1; p less than 0.001), while the ionized-calcium level in the control dialysis patients was below normal (4.5 +/- 0.4 vs. 4.9 +/- 0.1; p less than 0.001). Bone biopsies were performed in all patients. Two thirds of the hypercalcemic patients had low-turnover osteodystrophy (LTO, predominantly osteomalacia), a fraction significantly higher than in the control dialysis patients (13/21 vs. 8/28, respectively; p less than 0.05). The hypercalcemic patients with LTO had markedly elevated surface bone aluminum (63 +/- 24% of all trabecular surfaces). In contrast, the nonhypercalcemic dialysis patients with LTO and all patients with osteitis fibrosa had minimal surface bone aluminum. Hypercalcemic patients with osteitis fibrosa had a significantly lower mean N-terminal parathyroid hormone (PTH) value than did nonhypercalcemic patients with osteitis fibrosa (149 +/- 81 vs. 278 +/- 135 pg/ml, respectively; p less than 0.005). Both mean values were markedly elevated in comparison with those obtained in normal subjects (16 +/- 5 pg/ml). In contrast, patients with LTO, irrespective of the calcium level, had mean PTH values that were not significantly different from those of normal subjects. A PTH level greater than 100 pg/ml was 95% sensitive and 87% specific for osteitis fibrosa, as demonstrated by histomorphometry in nonhypercalcemic dialysis patients. However, this level was only 62% sensitive and 77% specific for a diagnosis of osteitis fibrosa in hypercalcemic dialysis patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Excessive ATP degradation during hemodialysis against sodium acetate

As the initial step in examining the metabolic basis for acetate intolerance, we have tested the hypothesis that excessive adenosine triphosphate (ATP) degradation occurs during hemodialysis against acetate dialysate (compared with the degree of degradation occurring during dialysis against bicarbonate dialysate). Seven patients undergoing long-term dialysis were infused with carbon 14--labeled 8-adenine, and their response to dialysis against acetate was compared with their response to dialysis against bicarbonate. The following changes were observed. During dialysis against acetate, the mean dialysate uric acid--to-creatinine ratio levels were significantly higher than the mean levels observed after dialysis against bicarbonate (p less than 0.001). The mean dialysate uric acid radioactivity--to-creatinine ratio and inosine, hypoxanthine, and xanthine radioactivity--to-creatinine ratio levels were significantly increased during dialysis against acetate (p less than 0.001). There was no significant change in plasma venous hypoxanthine level, but during dialysis against acetate, the arterial hypoxanthine levels (3.7 +/- 1.6 mumol/L) at 60 minutes were significantly higher than the levels observed after dialysis against bicarbonate (1.4 +/- 0.5 mumol/L) (p less than 0.01). These data provide evidence that excessive ATP degradation occurs during hemodialysis against acetate but not during hemodialysis against bicarbonate dialysate.

Effects of early antigen exposure through lactation on later specific antibody responses in mice

This study characterized totally the effects of early Ag exposure by the suckling route on later specific antibody responses. When mother mice of BALB/c or C57BL/6 strains were injected with deaggregated human gamma-globulin (HGG) immediately after delivery, total amounts of HGG in sera of offspring increased until 2 wk of age. The catabolism of transferred HGG was extremely slow and the half-life was about 3 wk in both strains. Hence, small amounts of Ag in mothers, 0.5 micrograms in C57BL/6 and 50 micrograms in BALB/c, could tolerize their offspring effectively. As these were minimum tolerogenic doses, the strain difference in ease of tolerance induction is apparent already during suckling. The study on timing dependent effects of HGG-specific antiserum on tolerance induction by mothers given 50 micrograms HGG demonstrated that the tolerance is achieved within the 1st wk of lactation in C57BL/6 offspring, but not in BALB/c offspring, and the restoration from the tolerance needs more than 6 wk under circumstances, supposedly, without free Ag. Whereas the tolerance was induced in a dose-dependent manner in each class of antibody, the dissociation of tolerant states between IgM, IgG, and IgE antibody classes was found in C57BL/6 offspring. It is interesting that C57BL/6 offspring were sensitized weakly, but significantly, by mothers given subtolerogenic doses. However, this was not apparent in BALB/c. Thus, the Ag dose and the animal strain are related closely to the consequences of this Ag exposure. The aging of suckling mice within the first 2 wk of life or immunomodulators administered early in life did not seriously affect the consequences. Studies on a cellular basis showed that the tolerance is caused by the selective defect in helper T cell function and the suppressor cell activity is not associated with the mechanisms. This contrasts with other models of oral tolerance.

Effects of early antigen exposure through lactation on later specific antibody responses in mice

This study characterized totally the effects of early Ag exposure by the suckling route on later specific antibody responses. When mother mice of BALB/c or C57BL/6 strains were injected with deaggregated human gamma-globulin (HGG) immediately after delivery, total amounts of HGG in sera of offspring increased until 2 wk of age. The catabolism of transferred HGG was extremely slow and the half-life was about 3 wk in both strains. Hence, small amounts of Ag in mothers, 0.5 micrograms in C57BL/6 and 50 micrograms in BALB/c, could tolerize their offspring effectively. As these were minimum tolerogenic doses, the strain difference in ease of tolerance induction is apparent already during suckling. The study on timing dependent effects of HGG-specific antiserum on tolerance induction by mothers given 50 micrograms HGG demonstrated that the tolerance is achieved within the 1st wk of lactation in C57BL/6 offspring, but not in BALB/c offspring, and the restoration from the tolerance needs more than 6 wk under circumstances, supposedly, without free Ag. Whereas the tolerance was induced in a dose-dependent manner in each class of antibody, the dissociation of tolerant states between IgM, IgG, and IgE antibody classes was found in C57BL/6 offspring. It is interesting that C57BL/6 offspring were sensitized weakly, but significantly, by mothers given subtolerogenic doses. However, this was not apparent in BALB/c. Thus, the Ag dose and the animal strain are related closely to the consequences of this Ag exposure. The aging of suckling mice within the first 2 wk of life or immunomodulators administered early in life did not seriously affect the consequences. Studies on a cellular basis showed that the tolerance is caused by the selective defect in helper T cell function and the suppressor cell activity is not associated with the mechanisms. This contrasts with other models of oral tolerance.

Simultaneous chemotherapy-radiotherapy with prophylactic cranial irradiation for inoperable adeno and large cell lung carcinoma: a Southwest Oncology Group Study

From September 1980 to March 1983, 30 cases were registered in a Southwest Oncology Group Study. Twenty-four cases were evaluable and constitute the basis for this report. Patients were diagnosed with adenocarcinoma or large cell lung carcinoma. Tumors were considered inoperable but able to be encompassed in a single radiotherapy (RT) port. Seventy-two percent of measured tumors were 4 cm in diameter or bigger (range 2 cm to 10 cm). RT was given initially to the primary lung tumor and ipsilateral hilar, mediastinal, and supraclavicular nodes, at 2 Gy per day; total dose was 44 Gy. The areas involved by tumor were boosted with 10 Gy more. Prophylactic cranial irradiation (PCI) was started at the same time with 15 treatments of 2.75 Gy. A 2-week rest period was instituted after the first 11 treatments. Chemotherapy (CT) was given from day 1 which consisted of 5-Flourouracil, 500 mg./M2, (bolus day 1 and 8) Vincristine, 1 mg./M2, and Mitomycin C, 5 mg./M2 both given on day 1. Cycles were repeated at 28 day intervals for 3 cycles and at 6 week intervals for 5 more cycles, or until progression, with persistent disease. Eight cases (33%) achieved complete response (CR), and 5 (21%) partial response (PR). Overall median survival was 37 weeks and 2 years survival was 8%. CR patients had the best chance for long-term survival. Relapses were evenly distributed between extra and intrathoracic sites, with the latter even between the inside and outside the RT field. No patient died with clinical evidence of metastasis to the brain (MB), although one was found to have MB at autopsy. Toxicity was severe in 7 cases (29%) and 2 deaths are considered toxicity related. When comparing these results to those from the literature, we found this protocol has achieved a slightly higher CR rate than what is expected with RT alone, without survival improvement. As CR patients have the best prognosis, simultaneous CT-RT might offer some promise, but at the expense of increased toxicity. PCI was effective in preventing or delaying MB, and thus deserves further investigation. We should caution that the study of possible long-term effects of PCI could not be assessed because of the short median survival of the patients. It is possible that a less aggressive time-dose fractionation to the brain might be as effective as the one used in this protocol.

Antiarrhythmic potential of chloroquine: new use for an old drug

Amiodarone and chlorpromazine are phospholipase inhibitors which produce cytoplasmic inclusion bodies and have important electrophysiologic properties. Chloroquine also inhibits phospholipase activity, resulting in similar inclusion bodies, but electrophysiologic information about this drug is lacking. In this study, the cellular electrophysiologic effects of two doses of chloroquine were examined in sheep Purkinje fibres and ventricular muscle cells. Both concentrations produced a significant reduction in maximum velocity of upstroke of the action potential and prolongation of the action potential duration and refractory period in Purkinje fibres. These effects were observed in the absence of significant changes in threshold of stimulation or action potential amplitude and were partially reversible following washout of the lower drug concentration. In addition to these experimental data, clinical evidence of antiarrhythmic action was determined by administering 500 mg chloroquine daily over nine weeks to six subjects with frequent asymptomatic ventricular premature complexes. In four patients there was a reduction in ventricular ectopy, which recurred when the drug was discontinued, while a fifth patient reverted to sinus rhythm from atrial fibrillation previously resistant to other antiarrhythmic medication. Thus, chloroquine has important electrophysiologic properties. The underlying mechanism of this action remains unproven at the present time.

Fractures and vertebral bone mineral density in patients with renal osteodystrophy

We investigated the relationship of CT determined vertebral bone mineral density (BMD), type of renal osteodystrophy, N terminal PTH levels and fracture history in 31 dialysis patients. BMD for patients with bone biopsy documented osteitis fibrosa was 1.6 standard deviation (SD) above the normal value for age and sex matched controls, while those patients with low turnover osteodystrophy had a mean BMD 1.2 SD below normal (p less than 0.0001). Three patients with osteitis fibrosa who had previously been treated with prednisone had a low BMD (1.8 SD below normal, different than O, p = 0.0015). There was no correlation between BMD and time on dialysis (r = 0.1). An N terminal PTH level greater than 150 pg/ml was a sensitive (94%) and specific (100%) method of separating those patients with osteitis fibrosa from those with low turnover osteodystrophy, while BMD was much less useful in this differentiation. A low BMD was not predictive of fracture history but the type of renal osteodystrophy was. Patients with low turnover osteodystrophy had a fracture rate of 0.2 fractures/dialysis year in comparison to those with osteitis fibrosis who had 0.1 fractures/dialysis year. Patients with the former bone disease fractured mainly axial rather than appendicular bones in contrast to those patients with osteitis fibrosa. In conclusion we found that patients with osteitis fibrosa had increased BMD compared to normal while those with low turnover osteodystrophy had decreased BMD, but that the N terminal PTH level was a better predictor of the type of bone disease present than was BMD.

CheA protein, a central regulator of bacterial chemotaxis, belongs to a family of proteins that control gene expression in response to changing environmental conditions

During bacterial chemotaxis, the binding of stimulatory ligands to chemoreceptors at the cell periphery leads to a response at the flagellar motor. Three proteins appear to be required for receptor-mediated control of swimming behavior, the products of the cheA, cheW, and cheY genes. Here we present the complete nucleotide sequence of the Salmonella typhimurium cheA gene together with the purification and characterization of its protein product. The protein is a 73,000 Mr cytoplasmic constituent. Amino acid-sequence comparisons indicate that it belongs to a family of bacterial regulatory proteins including the products of the cpxA, dctB, envZ, ntrB, phoR, phoM, and virA genes. Each member of this family has a conserved domain of approximately equal to 200 residues within its C terminus. We have previously shown that another chemotaxis protein, CheY, represents a domain of protein structure that has been conserved within a second large family of bacterial regulatory proteins. Each protein of the CheA family seems to function as a regulator of a different CheY homologue. Although each pair of proteins appears to produce a specialized response to a distinct type of stimulus, the relationships in primary structure suggest that a similar molecular mechanism may be involved.

Pressure Buildup Analysis For Wells Influenced By Fractures And Other Heterogeneities

Abstract

A new approach has been devised to analyze pressure buildups in heterogeneous reservoirs. The proposed procedure is a modification of the semi-log straight line plotting of Horner analysis. It is also an improvement over the conventional type curve matching technique in that the effect of flow time, and the rate variations during drawdown, are incorporated. Applications of this procedure to analyze heterogeneities characterized by a linear boundary, natural fractures, and a vertical fracture demonstrate the strength of the approach.

Introduction

The Horner plot(1,2) has been used successfully in the analysis of buildups taken after constant rate drawdowns from infinite acting, homogeneous reservoirs. If all the underlying assumptions are valid, then a plot of shut-in pressure versus the logarithm of the Horner time group results in a straight line. Parametric estimations can be made from the slope and intercept of this line.

Any type of heterogeneity in the reservoir introduces deviations from linearity in such a plot. For mild near wellbore heterogeneities such as wellbore storage or skin, only the early time data is affected. If, however, the duration of the shut-in time is short, then the initial deviation from linearity may cause some uncertainty in determining the start of the semi-log straight line. Ramey(3) introduced the type curve matching technique to resolve this problem. It has been used mainly to detennine the start of the semi-log straight line. Homer analysis is still required for parametric estimation purposes.

In situations with more complex heterogeneities, the deviation from linearity in Homer plots is more serious. In some cases, such as pressure buildups taken from wells intersecting vertical fractures, the data points in a Horner plot curve continuously upward, making the choice of an appropriate semi-log straight line difficult, if not impossible. Clearly, Horner analysis is inadequate in these situations and, instead of being a supporting tool, type curves themselves are being used increasingly for parametric estimation.

Because most of the type curves are a dimensionless pressure solution to the constant rate drawdown boundary condition, their use for buildup analysis requires an extra assumption of the total flow time being much longer than the shut-in time. When this assumption is not valid, McKinley(4), and Raghaven(5) suggested using buildup type curves. Thus, from one single drawdown curve it is necessary to generate a number of buildup type curves for different flow times. As the number of drawdown type curves multiplies, the choice of a best match among the multitude of buildup curves is not an easy one.

Another problem associated with the constant rate assumption is that it can be impractical to maintain the rate constant during the field test. Bostic et. al.(6) attempted to modify the drawdown type curves to take into account rate variations. Their derivation, however, depends on an erroneous substitution of the measured pressure into the dimensionless pressure. Hence the subsequent derivation cannot be used.

Recently, Rosa and Horne(7), Kucuk et al.(8), and Lee and Brockenbrough(9) devised least squares optimization schemes to resolve the above-mentioned problems with type curve matching.

Sequence requirements of Escherichia coli attTn7, a specific site of transposon Tn7 insertion

Transposon Tn7 transposes at high frequency to a specific site, attTn7, in the Escherichia coli chromosome. We devised a quantitative assay for Tn7 transposition in which Tn7-end derivatives containing the cis-acting transposition sequences of Tn7 transpose from a bacteriophage lambda vector upon infection into cells containing the Tn7-encoded transposition proteins. We used this assay to identify a 68-base-pair DNA segment containing the sequences essential for attTn7 target activity. This segment is positioned asymmetrically with respect to the specific point of Tn7 insertion in attTn7 and lacks obvious homology to the sequences at the ends of Tn7 which participate directly in transposition. We also show that some sequences essential for attTn7 target activity are contained within the protein-coding sequence of a bacterial gene.

Combined chemoradiotherapy in limited-disease, inoperable non-small cell lung cancer

Forty-three patients with limited-disease, inoperable non-small cell lung cancer received two intravenous courses of cyclophosphamide, Adriamycin, and cisplatin (CAP) chemotherapy over a 6-week period. This was followed by 5 weeks of combined chemoradiotherapy (CCRT) consisting of low weekly doses of CAP for 5 weeks plus 50 Gy continuous X ray therapy (XRT) to the primary tumor site. Chemotherapy was continued until disease progression occurred or until the total dose of Adriamycin reached 450 mg/m2, whichever came first. CCRT improved the response rate [complete response (CR) plus partial responses (PR)] from 25% after two courses of CAP alone to 65% after CCRT. Previous response to two courses of CAP influences response subsequent to CAP plus XRT. A pretherapy weight loss of 6% or greater had a significant adverse effect on both response and survival time. The median survival time for all patients was 50 weeks; patients whose disease responded to treatment survived significantly longer than patients with nonresponding disease. The median time until disease progression was 37 weeks. Twenty-seven patients relapsed. The first sites of relapse were local in 30% of the patients, distant in 56% of them, and both local and distant in 15%. Severe esophagitis occurred in 30% of the patients and was dose-limiting. The administration of CCRT resulted in an improved response rate compared with the rates reported in previous studies of chemotherapy or radiotherapy alone. Further improvement of the CCRT program is needed to increase long-term survival time and to decrease esophageal toxicity.

The welfare effects of illegal immigration

"This paper extends the work of Ethier on illegal immigration by examining the optimal level of enforcement for the labor-importing country in a two-country model and by considering the effects of allowing capital mobility. We derive a formula for the optimal level of enforcement against firms that hire illegal workers, and show that the presence of enforcement costs makes the policy less efficient than a wage tax. With capital mobility, foreign workers gain from an increase in enforcement in the home country because capital is driven out of the home country."

Kinetics of procaterol auto-oxidation in buffered acid solutions

The kinetics of procaterol (1) degradation in buffered acidic solutions (pH 4-6) was investigated using an HPLC procedure. The effect of temperature and ferric ions on the reaction rate was estimated. In acidic solutions, 1 undergoes pseudo first-order degradation with an induction period. The first-order rate constant for degradation increased and the induction period decreased with an increase in pH. Ferric ions catalyzed the degradation reaction and decreased the induction period. At pH 6, the activation energy of the reaction was 34.5 kcal/mol/deg. The results of this study indicate that 1 in solution is more stable at acidic pH, in the absence of heavy metal ions, and protected from air.

Immunochemical probing of the N-terminus of the myosin heavy chain

The reactivity of myosin subfragment 1 (S-1) towards site specific polyclonal anti-N-terminus antibodies was examined in competitive ELISA titrations. Tryptic digestion of S-1 and specifically the cleavage at the 25/50K junction greatly increased the accessibility of the N-terminus region to the antibodies. The binding of actin to S-1 did not change significantly the reactivity of either tryptic or intact S-1 towards anti-N-terminus antibodies. These results suggest the interdependence of the N-terminus and 25/50K junction regions on S-1.

Long-term follow-up of lens changes with Scheimpflug photography in diabetics

This study was designed to document and quantify changes in lens clarity over 24 months in a group of diabetic patients. One hundred thirty-four type I and type II diabetics of 3 months' to 45 years' duration with an average age of 53.5 +/- 7 years volunteered to participate in this prospective study. Patients were evaluated upon entry and at 6-month intervals. Scheimpflug lens photographs (Topcon SL45) were taken at each visit. All photographs were evaluated by densitometry which allowed quantification of the light scattering in the various lens layers. A significant and progressive (4-7% every 6 months) increase in light scattering was observed in the lens anterior superficial lens cortex over 24 months. The rate of change in lens clarity was similar in all patients regardless of the clinically observable lens change type (nuclear, cortical, posterior subcapsular, or mixed). Patients who were younger at enrollment, having diabetes of shorter duration and higher glycosylated hemoglobin values (a measure of long-term glucose control), were identified to be at greater risk of having increased densitometry values in the anterior superficial lens cortex. Only a few patients had significant changes in visual acuity during 24 months, and the correlation of superficial cortical lens clarity changes to clinical cataract formation and visual impairment remains to be established.

Proteolysis and binding of myosin subfragment 1 to actin

Rates of proteolytic cleavage of myosin subfragment 1 were measured in the absence and presence of different amounts of actin. The rates of tryptic digestion at the 50K/20K junction and papain digestion at the 25K/50K junction of the myosin head were progressively inhibited with increasing substoichiometric molar ratios of actin to myosin subfragment 1. The percentage inhibitions of digestion reactions corresponded precisely to the molar compositions of actin-subfragment 1 solutions and demonstrated that equimolar complexes of these proteins were responsible for the observed changes in the proteolysis of myosin heads.

Identification of a possible nucleotide binding site in CheW, a protein required for sensory transduction in bacterial chemotaxis

CheW is an essential component of the system which mediates chemotaxis in Salmonella typhimurium and Escherichia coli. Here we report the nucleotide sequence of the cheW gene as well as the purification and characterization of the CheW protein. The DNA sequence predicts a protein of 18,000 molecular weight. The pure protein exhibits an apparent molecular weight of 18,000 during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Molecular sieve chromatography under nondenaturing conditions indicates a molecular weight of approximately 35,000, however. This result suggests that CheW is a homodimer. The predicted amino acid sequence between Thr-128 and Asp-160 fits a consensus exhibited by many proteins which bind purine nucleotides.

Differential sulfation and sialylation of secreted mouse thyrotropin (TSH) subunits: regulation by TSH-releasing hormone

To determine whether sulfate and/or sialic acid are present on secreted mouse TSH, thyrotropic tumor minces and hypothyroid pituitaries were incubated with [3H]methionine and [35S]sulfate, or [35S]methionine and [3H]N-acetylmannosamine. The metabolically labeled TSH and free alpha-subunits were then analyzed by gel electrophoresis. [3H]N-Acetylmannosamine was a specific precursor (greater than 80%) for the sialic acid [3H]N-acetylneuraminic acid, as established by HPLC characterization of tritium label released by acid hydrolysis. Each of the three secreted subunits (TSH alpha, TSH beta, and free alpha) incorporated both sulfate and sialic acid. The incorporation of these labels was confirmed by the release of [35S]sulfate by endoglycosidase F and of [3H]N-acetylneuraminic acid by neuraminidase. Differential labeling of newly synthesized secreted TSH subunits was observed. In secreted TSH dimer, TSH beta incorporated 1.3 times more [35S]sulfate (P less than 0.05) and 2.5 times more [3H] N-acetylmannosamine (P less than 0.02) per carbohydrate chain than did TSH alpha. Secreted free alpha-subunit incorporated more [3H]N-acetylmannosamine, but less [35S]sulfate, then did secreted TSH alpha. To investigate the effect of TRH on TSH sulfation and sialylation, thyrotropic tumor minces and hypothyroid pituitaries were incubated with [35S]sulfate or [3H]N-acetylmannosamine, with or without 10(-7) M TRH; labeling was then normalized in each case to incorporation of [3H]mannose, a marker of the inner core sugars. TSH secreted in the presence of TRH had a lower sulfate to mannose ratio [28 +/- (+/- SE) 4% of control; P less than 0.05] and a lower sialic acid to mannose ratio (63 +/- 8% of control; P less than 0.05). TSH alpha and TSH beta were affected equally. No change was seen in the labeling of non-TSH secretory proteins. Differential glycoprotein sulfation and sialylation may, in part, explain the previously observed variability in isoelectric point, bioactivity, and MCR of TSH in different physiological states and may represent a point of regulation by TRH.

Significance of megamitochondria in alcoholic liver disease

The significance of megamitochondria in the alcoholic liver injury of humans was investigated as part of a large Veterans Administration cooperative study of the natural history of alcoholic hepatitis. Two hundred twenty patients were clinically stratified into the following three groups according to disease severity using serum bilirubin and prothrombin time as indicators: Group 1 (mild disease), serum bilirubin levels less than 5 mg/dl and prothrombin time prolonged for less than 4 s; group 2 (moderate disease), serum bilirubin levels greater than 5 mg/dl but prothrombin time prolonged for less than 4 s; and group 3 (severe disease), serum bilirubin levels greater than 5 mg/dl and prothrombin time prolonged for greater than 4 s. Megamitochondria were observed in 20% of the patients (45 of 220). Of these, 43 patients were in groups 1 and 2 of severity and only 1 patient belonged in group 3. The association of megamitochondria with cirrhosis was infrequent (33%, 15 of 45 patients). The differences in severity correlated with the differences in mortality: in patients with megamitochondria, only 1 had died at 6 mo compared with 40 deaths in patients without megamitochondria. By 12 mo, there were two deaths in patients with megamitochondria versus 51 deaths in those patients without. No complications were present in 72% of patients with megamitochondria versus 39% for those without. Infection, gastrointestinal bleeding, pancreatitis, hyperglycemia, azotemia, delirium tremens, seizures, and hepatic encephalopathy were all more common in patients without megamitochondria. The patients with megamitochondria appear to represent a subcategory of alcoholic hepatitis with a milder degree of clinical severity, lower incidence of cirrhosis, fewer complications, and good long-term survival.

Spontaneous hypercalcemia in patients undergoing dialysis. Etiologic and therapeutic considerations

Ten dialysis-treated patients with hypercalcemia (11.5 +/- 0.3 mg/dl, mean +/- SE) due to renal osteodystrophy were compared with 30 control dialysis-treated patients who were not hypercalcemic (9.5 +/- 0.1 mg/dl). The hypercalcemic patients were more disabled than the control patients. Fifty percent of the hypercalcemic patients and 37 percent of the control patients had a mineralization defect (p greater than 0.6). In the control group, intact parathyroid hormone level was significantly higher in patients with osteitis fibrosa than in those with osteomalacia (247 +/- 39 pg/ml versus 60 +/- 20 pg/ml, respectively, p less than 0.005) whereas in the hypercalcemic patients, parathyroid hormone measurements did not discriminate between these two types of bone disease. Osteomalacia was more severe and bone aluminum staining was stronger in the hypercalcemic patients than in the control patients (2.02 +/- 0.47 versus 0.35 +/- 0.11 mm/mm2 tissue area, p less than 0.001). The mean serum calcium level fell from 11.2 +/- 0.2 mg/dl to 10.5 +/- 0.3 mg/dl (p less than 0.01) in eight hypercalcemic patients treated with 24,25-dihydroxyvitamin D. It is concluded that hypercalcemia in patients undergoing dialysis is associated with an increase in bone aluminum level, and with more severe osteomalacia. Intact parathyroid hormone levels are useful for predicting bone histomorphometric parameters but only when hypercalcemia is not present. The drug, 24,25-dihydroxyvitamin D, was effective in lowering the serum calcium level.

Comparative maternal and neonatal effects of halothane and enflurane for cesarean section

The effects of placental transfer of enflurane and halothane were studied in 81 women undergoing cesarean sections. All patients had rapid sequence induction using thiopental, succinylcholine, and endotracheal intubation. They were then randomly assigned to one of five groups: Group I (n = 16) received N2O and oxygen, Group II (n = 16) N2O, oxygen, and 0.25% halothane, Group III (n = 18) N2O, oxygen, and 0.5% halothane, Group IV (n = 18) N2O, oxygen, and 0.5% enflurane, Group V (n = 13) N2O, oxygen, and 1% enflurane. At delivery, blood was drawn from the maternal artery, umbilical vein and artery for measurement of the halogenated agents using gas chromatography. The neonates were evaluated by Apgar scores, umbilical artery and vein acid base status and the Early Neonatal Neurobehavioral Scores (ENNS) at 2 and 24 h of age. Blood loss and the incidence of maternal awareness were also determined. The umbilical vein to maternal vein ratio was approximately 0.5 and 0.6 for enflurane and halothane, respectively. The umbilical artery to umbilical vein ratio was 0.5 with both agents; higher inspired anesthetic concentrations produced higher blood levels. All neonates had Apgar scores of 8 or more at 5 min with the exception of one neonate in the N2O group. Maternal and neonatal acid base status, blood loss, and ENNS were not affected by the addition of the halogenated agents. Of the patients who had N2O alone, 12% had awareness versus none in the other groups. These data demonstrate that low dose halothane or enflurane decreases the incidence of maternal awareness and does not adversely affect the neonate.

Cross-linking of actin to myosin subfragment 1 in the presence of nucleotides

Chemical cross-linking of actin to the 20K and 50K fragments of tryptically cleaved myosin subfragment 1 (S-1) by the zero-length cross-linking reagent 1-ethyl-3-[3-dimethylamino)propyl]carbodiimide (EDC) was used as a probe of the acto-S-1 interface in the presence of nucleotides. The course of the two reactions was monitored by measuring on sodium dodecyl sulfate (SDS)-polyacrylamide gels the time-dependent formation of the 20K-actin and 50K-actin cross-linked products. Both reactions were inhibited somewhat in the presence of MgADP, were slowed 3-4-fold in the presence of magnesium 5'-adenylyl imidodiphosphate (MgAMPPNP), and proceeded at least 7-fold slower with N,N'-p-phenylenedimaleimide (pPDM) modified S-1, as compared to the respective rates in the absence of nucleotides. However, neither the binding of the nucleotides MgADP and MgAMPPNP to S-1 nor the modification of S-1 by pPDM significantly changed the ratio of the cross-linking rates of actin to the 20K and 50K fragments. Similar to what was previously observed in the absence of nucleotides [Chen, T., Applegate, D., & Reisler, E. (1985) Biochemistry 24, 137-144], actin was cross-linked at an approximately 3-fold faster rate to the 20K fragment than to the 50K fragment under all reaction conditions tested. Thus, irrespective of the extent of acto-S-1 dissociation or the binding of nucleotides to acto-S-1, the 20K fragment remains the preferred cross-linking site for actin. These results show that the interaction of actin with each of the cross-linking sites on S-1 is not under selective or preferential control by nucleotides.

Lethal atherosclerosis associated with abnormal plasma and tissue sterol composition in sitosterolemia with xanthomatosis

Tissue sterol composition was determined in an 18-year-old male with sitosterolemia with xanthomatosis who died suddenly and whose coronary and aortic vessels showed extensive atherosclerosis and, for comparison, in an 18-year-old male with minimal atherosclerosis who died accidently. Sterols in the control tissues (plasma, erythrocytes, cardiac muscle, lung, liver, aorta, and brain) contained cholesterol with only trace amounts of cholestanol. In contrast, sterols in corresponding tissues of the sitosterolemic subject (except brain) were composed of cholesterol, increased amounts of plant sterols, campesterol and sitosterol, and 5 alpha-saturated stanols, cholestanol, 5 alpha-campestanol, and 5 alpha-sitostanol, that were deposited in approximately the same ratio as present in plasma. However, sitosterolemic brain sterol composition resembled that of the control brain with cholesterol and only trace amounts (less than 1%) of cholestanol and phytosterols. The sitosterolemic aorta was extensively atherosclerotic and contained more than twice the quantity of sterols as the control aorta (5.6 mg/g versus 2.6 mg/g) with increased amounts of cholesterol, plant sterols, and 5 alpha-saturated stanols. These results indicate that cholesterol, plant sterols, and 5 alpha-stanols are deposited prematurely and are associated with accelerated atherosclerosis in subjects with sitosterolemia with xanthomatosis.

Comparison of intra-arterial cis-diamminedichloroplatinum II with high-dose methotrexate and citrovorum factor rescue in the treatment of primary osteosarcoma

A randomized two-arm study was undertaken to determine relative tumoricidal effects of intra-arterial cis-diamminedichloroplatinum II (I/A-CDP) and high-dose methotrexate with citrovorum factor rescue (MTX-CF) in the treatment of the primary tumor in patients with osteosarcoma. Responses were evaluated by clinical, radiographic, angiographic, and pathologic parameters. Fifteen patients were randomized to receive MTX-CF and 15 to I/A-CDP. In the MTX-CF arm there were four responses (three complete responses, one partial response) whereas in the I/A CDP arm there were nine responses (seven complete responses, two partial responses). Two patients who failed MTX-CF and requested alternative treatment with I/A-CDP also responded. The total I/A-CDP response was 11/17.

High rate of long-term survival in adult acute leukemia following ten-day chemotherapy (OAP) induction. Maintenance with chemotherapy or chemotherapy plus BCG vaccine

In this Southwest Oncology Group (SWOG) study, 216 adults with acute leukemia were treated with ten-day chemotherapy consisting of vincristine sulfate (Oncovin), cytarabine (ara-C) (100 mg per square meter of body area per day by 24-hour infusion), and prednisone (ten-day OAP). The results were compared with those of a previous SWOG study in which cytarabine (200 mg per square meter of body area per day) was given for five days (five-day OAP). Patients entering complete remission (CR) were given three consolidation courses of five-day OAP and randomized to maintenance chemotherapy alone (32 patients) or combined with BCG vaccine (24 patients). For 160 previously untreated patients with acute myelogenous leukemia, there was no difference in remission rates (53% vs 43%) or median survival times (48 vs 47 weeks) between ten-day and five-day OAP. The difference in duration of CR (74 vs 54 weeks, respectively) between the two maintenance arms was not statistically significant. However, 14% of evaluable patients with acute myelogenous leukemia and 26% of those achieving CR were alive and in remission more than five years.