The cause of dysphagia in uncomplicated sliding hiatal hernia and its relief by hiatal herniorrhaphy. A roentgenographic, manometric, and clinical study

Patients with an uncomplicated sliding hiatal hernia frequently experience dysphagia. The present study shows, using video barium contrast esophagograms, that the cause of dysphagia in 60% of these patients is an obstruction to the passage of the swallowed bolus by diaphragmatic impingement on the herniated stomach. Manometrically this was reflected by a double-hump high pressure zone (HPZ) at the gastroesophageal junction, and specifically to the length and amplitude of the distal HPZ and the length of the intervening segment between the two HPZs. The former represents the degree of the diaphragmatic impingement on the herniated stomach and the latter the size of the supradiaphragmatic herniated stomach. Surgical reduction of the hernia resulted in relief of dysphagia in 91% of the patients.

Iopamidol as a gastrointestinal contrast agent. Lack of peritoneal reactivity

The ideal contrast agent in patients suspected of having gastrointestinal perforation is an iso-osmolar, or nearly iso-osmolar substance, that causes no peritoneal reaction. Iopamidol is a nonionic water-soluble contrast medium that may be considered in such situations. Intraperitoneal injections of ionic and nonionic contrast agents were compared in rats to study potentially harmful peritoneal inflammation. Only intraperitoneal barium injection produced any significant tissue reaction, such as adhesions and ascites. There was no difference between iopamidol and the other water-soluble contrast agents. Iopamidol may satisfy the need for nonreactive and nearly iso-osmolar contrast agents for evaluating patients with possible bowel perforation. However, the high cost of this agent may make its clinical application impractical.

Electrophysiological study of the denervated orbicularis oculi muscle in dogs

This study investigated the electrophysiology of the denervated orbicularis oculi muscle and its clinical application. Orbicularis oculi muscle denervation was achieved by complete transection of the seventh nerve in ten dogs. The parameters studied were the electrical requirements needed to cause a minimal perceptible contraction (twitch) and a complete eyelid closure (blink). Twitch and blink curves were generated. The findings are summarized as follows: (1) Minimum intensities for direct twitch of denervated orbicularis oculi muscle were significantly lower than intensities of normal orbicularis oculi muscle twitch (p less than 0.01) when long stimulus duration (5 to 400 ms) was used. (2) Minimum intensities for direct blink of denervated orbicularis oculi muscle were not significantly different from stimulus intensities for blink of normal orbicularis oculi muscle if long stimulus duration (5 to 400 ms) was used. Twitch and blink curves could be used to clinically follow the orbicularis oculi muscle movement return after operations performed in patients affected by lagophthalmos.

Myocardial uptake and clearance of T1-201 in healthy subjects: comparison of adenosine-induced hyperemia and exercise stress

Pharmacologic stress testing with dipyridamole is useful in patients undergoing thallium-201 myocardial perfusion scintigraphy who cannot adequately exercise. Because dipyridamole increases coronary blood flow by reducing the metabolism of adenosine, the authors compared the uptake and clearance of T1-201 following exercise stress testing (EST) and resting intravenous infusion of adenosine (AI) in crossover fashion in 20 healthy men. No perfusion defects or areas of redistribution were noted in any of the scans. Mean absolute myocardial T1-201 uptake was 1.3 times greater with AI than with EST. Mean absolute extracardiac uptake was 2.0 times greater with AI. Mean T1-201 myocardial clearance was virtually the same in all AI and EST views. During AI, 70% of the subjects experienced subjective side effects, mean arterial blood pressure decreased by 15%, and heart rate increased by 48%. The effects of adenosine on T1-201 kinetics in the myocardium are similar to those of EST. Adenosine may be useful as a pharmacologic stress agent in patients undergoing T1-201 myocardial perfusion scintigraphy.

DNA adducts from carcinogenic and noncarcinogenic enantiomers of benzo[a]pyrene dihydrodiol epoxide

The characterization of eight benzo[a]pyrene-deoxyribonucleoside adducts derived from reaction of the anti-dihydrodiol epoxide and deoxyguanylic and deoxyadenylic acids is described. It is reported that the epoxide ring is opened by the purine amino groups to yield similar amounts of both cis and trans products. NMR data show that the 7- and 8-hydroxyl groups are pseudodiaxial in the cis products and pseudodiequatorial in the trans products, and we suggest that these products arise from reaction with the diaxial and diequatorial conformers of the dihydrodiol epoxides, respectively. The chiral nature of the interactions of these metabolites with DNA restricts the range of products formed with this macromolecule, and a trans product with deoxyguanosine is the major product formed with either enantiomer of the anti-dihydrodiol epoxide.

Absolute stereochemistry of the major 7,12-dimethylbenz[alpha]anthracene- DNA adducts formed in mouse cells

In recent work we assigned partial structures to individual 7,12-dimethylbenz[alpha]anthracene (DMBA)--deoxyribonucleoside bisphosphates separated by TLC after postlabeling with [32P]ATP. We have now been able to postlabel DNA adducts formed in cells exposed to either the (4R,3R)- or (4S,3S)-dihydrodiol of DMBA and thereby to assign absolute stereochemistry to the 2-, 3- and 4- positions in the major DMBA-DNA adducts. It is found that the major anti dihydrodiol epoxide-DNA adducts arise from the (4R,3S)-dihydrodiol (2S,1R)-epoxide and that the major syn dihydrodiol epoxide-DNA adducts arise from the (4S,3R)-dihydrodiol (2S,1R)-epoxide.

Esophageal function in patients with reflux-induced strictures and its relevance to surgical treatment

Esophageal function was evaluated in 53 patients with increasing severity of esophageal injury caused by gastroesophageal reflux disease (study 1), and the findings were applied to the treatment of 28 patients with reflux-induced strictures (study 2). Fifty asymptomatic volunteers served as controls for both studies. In study 1 there were 14 patients without reflux complications, 14 with esophagitis grade I to III, 13 with esophageal stricture, and 12 with Barrett's epithelium (6 of whom had a stricture). The prevalence of a mechanically defective sphincter increased with the progression of the esophageal injury; 50% in the patients without complications to 84% and 92% in those with stricture or Barrett's epithelium, respectively. Similarly, a decrease in amplitude of contractions in the distal esophagus was observed in patients with stricture and patients with Barrett's epithelium. In study 2, these findings were applied in the surgical management of 28 consecutive patients with a reflux-induced stricture. Preoperative motility studies were performed after patients were dilated to 60F. Control of reflux by a Nissen fundoplication gave excellent (86%) to good (14%) results in patients who had relief of dysphagia after dilation or adequate motility, or both. Four patients with both persistent dysphagia after dilation and inadequate motility underwent resection. Transmural presented are helpful in the selection of the optimal surgical procedure for the treatment of dilatable reflux-induced strictures.

The relation of rural alcoholism to farm economy

Several studies have suggested an association between the farm crisis of the 1980's and the increase in mental health problems in rural America. A stress hypothesis for alcoholism would indeed predict such an association. The study presented herein examines the rate of new referrals for treatment of alcohol abuse and/or dependence to state-funded agencies in Nebraska. Between mid-1978 and mid-1986, the rate of subjects seeking treatment grew steadily, paralleling an increase in both population and available treatment programs. Yet, the total number of farmers seeking treatment peaked around 1982 and declined steadily thereafter, outpacing any change in the total number of farmers in the state. Possible interpretations of these findings are discussed.

A metabolite of the carcinogen 7,12-dimethylbenz[a]anthracene that reacts predominantly with adenine residues in DNA

Four 7,12-dimethylbenz[a]anthracene--deoxyribonucleoside adducts formed in mouse epidermis in vivo arise from the syn dihydrodiol epoxide metabolite of this carcinogen. With the synthetic syn dihydrodiol epoxide it was possible to identify three of these as deoxyadenosine adducts and to establish their structures. These three adducts account for the large majority of DNA adduct arising from this metabolite in vivo. The in vivo metabolite is unusual, therefore, in that it reacts almost exclusively with adenine residues in DNA while most carcinogen metabolites react preferentially with guanine residues.

Comparison of free alpha-tocopherol and alpha-tocopheryl acetate as sources of vitamin E in rats and humans

The uptake of alpha-tocopherol from 2R,4'R,8'R-alpha-tocopherol and 2R, 4'R, 8'R-alpha-tocopheryl acetate has been compared in rats and humans. The two forms of vitamin E were compared simultaneously in each subject (rat and human) by using a combination of deuterium-substitution and gas chromatography-mass spectrometry (GC-MS) to distinguish and measure the competitive uptake of alpha-tocopherol from an orally ingested mixture of the acetate and the free phenol forms. When rats were dosed in a manner analogous to that used in traditional bioassays, i.e., providing the two forms of vitamin E once daily in tocopherol-stripped corn oil for four successive days immediately prior to sacrifice, the net uptake of alpha-tocopherol from the free phenol form was only half that from the acetate. This result is consistent with the greater activity of the acetate that had been observed previously in bioassays. However, when the two forms of tocopherol were intubated into rats as a single dose mixed in with an aqueous bolus of standard laboratory diet, the amount of alpha-tocopherol taken up from the free form after 24 hr was very similar to that derived from the acetate. In five adult humans, competitive uptake studies of the two forms after a single dose taken with a meal showed that the amount of alpha-tocopherol from the free phenol form was equal to that from the acetate in plasma and red blood cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of 7,12-dimethylbenz[a]anthracene-adenine nucleoside adducts

Chromatographic comparisons were made between radioactive adducts derived from the DNA of cells treated with [3H]7,12-dimethylbenz[a]anthracene and adducts derived from calf thymus DNA or nucleotides which had been treated in vitro with the synthetic syn 3,4-dihydrodiol 1,2-epoxide of this same carcinogen. This confirmed that three of the adducts formed in cells were derived from reaction of this particular dihydrodiol epoxide with deoxyadenosine while a fourth adduct was derived from its reaction with deoxyguanosine. After reaction of the dihydrodiol epoxide with polyadenylic acid, two ribonucleoside adducts were characterized by spectroscopic methods and were shown to have arisen from the cis opening of the epoxide ring at C1 by the amino group of adenine residues.

EELS log-ratio technique for specimen-thickness measurement in the TEM

We discuss measurement of the local thickness t of a transmission microscope specimen from the log-ratio formula t = lambda ln (It/I0) where It and I0 are the total and zero-loss areas under the electron-energy loss spectrum. We have measured the total inelastic mean free path lambda in 11 materials of varying atomic number Z and have parameterized the results in the form lambda = 106F (E0/Em)/ln (2 beta E0/Em) where F = (1 + E0/1,022)/(1 + E0/511)2, the incident energy E0 is in keV, the spectrum collection semiangle beta is in mrad, and Em = 7.6Z0.36. This formulation should allow absolute thickness to be determined to an accuracy of +/- 20% in most inorganic specimens.

The lower esophageal sphincter in health and disease

The ability of the lower esophageal sphincter to protect the esophageal mucosa from exposure to gastric juice depends on its resting pressure, length exposed to abdominal pressure, and overall length. Mechanical incompetency of the sphincter can occur when one or more of these components fail. The purpose of this study was to measure manometrically the normal percentile values for these components, and to identify the point differentiating a mechanically competent from an incompetent sphincter. The results show that a mechanically incompetent sphincter can be identified by a sphincter pressure below the 2.5 percentile, an abdominal length below the fifth percentile, and an overall length below the 2.5 percentile of normal values. Sixty percent of the patients with documented increased esophageal exposure to acid gastric juice had a mechanically incompetent sphincter.

Familial idiopathic megaduodenum

Familial idiopathic megaduodenum is an uncommon condition which may be associated with other visceral abnormalities. Antineuronal antibody directed against guinea-pig skeletal muscle was found in one member of the family suffering from megaduodenum, in whom degeneration of the Auerbach's and Meissner's plexuses was documented. The significance of this finding is unclear. Management of the complaint is problematic. Despite shortcomings of surgical treatment, surgery nevertheless has an important role to play when medical treatments fail.

Spliceosome assembly in yeast

Precursors to mRNA become substrates for splicing by being assembled into a complex multisubunit structure, the spliceosome. To study the assembly of the yeast spliceosome, intermediate complexes were separated by electrophoresis on nondenaturing polyacrylamide gels. Four splicing-dependent complexes, A1, A2-1, A2-2, and B, were observed. The order of assembly of these complexes was determined to be B----A2-1----A1----A2-2. The assembly process can be blocked at complex A1 by addition of 5 mM EDTA or by carrying out the assembly process in heat-inactivated rna2 extracts. The snRNA composition of the complexes was determined by hybridization with probes for five yeast snRNAs. snR14 (U4) was only found in complex A2-1, snR6 (U6) and snR7 (U5) were in complexes A1, A2-1, and A2-2, whereas snR20 (U2) was in all four of the complexes. snR19 (U1) was not present in any of the complexes. Hybridization with these probes was also employed to detect snRNPs present in yeast splicing extracts. We found that snR6, snR7, and snR14 were present together in a large complex. This complex underwent an ATP-dependent dissociation to give snR7 and snR6-snR14 complexes. snR19 and snR20 are present in distinct RNPs but the mobility of these is not affected by ATP. A mechanism for spliceosome assembly is proposed.

Activity of a partially purified human BCGF on murine assays for B cell stimulatory factors. II. Synergy between two distinct BCGF II-like factors in promoting B cell differentiation

We have previously identified two BCGF II-like factors which can be distinguished by their differential reactivity in several murine BCGF II assays. Prototype sources of these two factors are a partially purified preparation derived from PHA-P-stimulated human peripheral blood T lymphocytes (designated human BCGF), and supernatant from antigen-stimulated D10.G4.1 murine T cells (designated D10 sup). Extending the characterization of these two factors, we show here that human BCGF and D10 sup both cause tritiated thymidine ([3H]TdR) incorporation and IgM secretion by T cell-depleted, in vivo-activated, large murine B cells. In contrast, only the human BCGF consistently induced proliferation and IgM secretion by T cell-depleted, small murine B cells. When simultaneously added to cultures, D10 sup and human BCGF synergized to produce optimal IgM secretion by large murine B cells and murine BCL1 B lymphoma cells. The same factors were tested in an IgM-specific plaque assay, and a similar synergistic response was observed for the large B cells, but not for the BCL1 cells. The combination of factors also produced maximal [3H]TdR incorporation by large murine B cells. In contrast, the addition of human BCGF totally abrogated D10 sup-induced BCL1 proliferation. Together, these data suggest that the synergies observed in IgM secretion result from an increased production of plaque-forming cells (PFC) in cultures of large B cells and an increase in IgM production per responding cell in BCL1 cells. Kinetic analysis of the time of action of the two BCGF II-like lymphokines in the induction of the PFC response by large B cells indicated that human BCGF was required within the first 24 hr of a 4-day culture period, while D10 sup could be added as late as the final 15 hr without significant diminution of the response. In summary, these data provide further support for the existence of two distinct B cell stimulatory factors which cause growth and differentiation of activated B cells, and indicate that these two factors synergize to produce optimal Ig secretion. For ease of discussion, the activity in the human BCGF preparation is referred to as BCGF IIA, and the activity in D10 sup is referred to as BCGF IIB.

Activity of a partially purified human BCGF on murine assays for B cell stimulatory factors. II. Synergy between two distinct BCGF II-like factors in promoting B cell differentiation

We have previously identified two BCGF II-like factors which can be distinguished by their differential reactivity in several murine BCGF II assays. Prototype sources of these two factors are a partially purified preparation derived from PHA-P-stimulated human peripheral blood T lymphocytes (designated human BCGF), and supernatant from antigen-stimulated D10.G4.1 murine T cells (designated D10 sup). Extending the characterization of these two factors, we show here that human BCGF and D10 sup both cause tritiated thymidine ([3H]TdR) incorporation and IgM secretion by T cell-depleted, in vivo-activated, large murine B cells. In contrast, only the human BCGF consistently induced proliferation and IgM secretion by T cell-depleted, small murine B cells. When simultaneously added to cultures, D10 sup and human BCGF synergized to produce optimal IgM secretion by large murine B cells and murine BCL1 B lymphoma cells. The same factors were tested in an IgM-specific plaque assay, and a similar synergistic response was observed for the large B cells, but not for the BCL1 cells. The combination of factors also produced maximal [3H]TdR incorporation by large murine B cells. In contrast, the addition of human BCGF totally abrogated D10 sup-induced BCL1 proliferation. Together, these data suggest that the synergies observed in IgM secretion result from an increased production of plaque-forming cells (PFC) in cultures of large B cells and an increase in IgM production per responding cell in BCL1 cells. Kinetic analysis of the time of action of the two BCGF II-like lymphokines in the induction of the PFC response by large B cells indicated that human BCGF was required within the first 24 hr of a 4-day culture period, while D10 sup could be added as late as the final 15 hr without significant diminution of the response. In summary, these data provide further support for the existence of two distinct B cell stimulatory factors which cause growth and differentiation of activated B cells, and indicate that these two factors synergize to produce optimal Ig secretion. For ease of discussion, the activity in the human BCGF preparation is referred to as BCGF IIA, and the activity in D10 sup is referred to as BCGF IIB.

Chiral discrimination in the exchange of alpha-tocopherol stereoisomers between plasma and red blood cells

The transport of 2R,4'R,8'-alpha-tocopherol and 2S,4'R,8'R-alpha-tocopherol from plasma into rat red blood cell membranes occurs with essentially no chiral discrimination. The previously demonstrated (10) preference of red blood cell membranes favoring 2R,4'R,8'R-alpha-tocopherol over the 2S,4'R,8'R stereoisomer is shown to be due to better retention of the former compound, i.e., to preferential retention of natural vitamin E.

Massive hollow fiber clotting: a distinct problem in treatment of cryoglobulinemia by membrane plasmapheresis

Two patients with cryoglobulinemia were treated with plasmapheresis in combination with immunosuppressive therapy. One had Waldenstrom's macroglobulinemia, and the other suffered from systemic lupus erythematosus. Membrane plasmapheresis, using membrane plasma separators, was performed, and the initial plasmapheresis treatments were unsatisfactory because of clotting of hollow fibers by cryoglobulin. The plasma filtration rate and the clearance of immunoglobulins fell rapidly with the clotting of the hollow fibers. This technical difficulty was overcome by prediluting the blood with normal saline before passing it through the membrane plasma separator. The mechanism of preventing clotting of hollow fiber by saline predilution is likely to be the reduction of serum viscosity and the lowering of cryoglobulin concentration. This modification is simple and efficient and enables membrane plasmapheresis to be performed effectively in patients with cryoglobulinemia without complicated and expensive machines.