The iridium/iridium oxide electrode for in vivo measurement of oesophageal and gastric pH

An iridium-iridium oxide electrode for in vivo pH measurement of the distal oesophagus is described. It is small and flexible so it is well accepted by patients for long-term pH monitoring. The electrode also offers the possibility of including another electrode and/or a pressure sensor for simultaneous detection of two or more parameters--gastric pH or oesophageal pressure for example. A clinical study was performed on 15 healthy volunteers and the results were checked on a DGC Nova 4/S computer, showing less than 0.005% of tension in mV out of the established range in a period of 24 h pH monitoring. The volunteers' results were compared with the normal values obtained by DeMeester using a glass electrode on a similar, healthy group of American patients and no significant differences were observed. Owing to its small size, reliability, fast response to pH changes, durability and its easy storage, the Ir/IrO2 electrode is ideal for long-term pH monitoring of the upper gastro-intestinal tract.

Retinoic-acid-binding protein in normal and neoplastic human esophagus

The concentration of cellular retinoic acid binding proteins (CRABP) was determined in the cytosol of normal esophageal tissue and in esophageal carcinomas. Unlike the reported results for human breast, colon, melanoma, or oropharynx cancers, the CRABP levels in esophageal cancers were either undetectable or contained levels of CRABP which were significantly lower than that of adjacent histologically disease-free tissue (P less than 0.005). Moreover, there was no difference between the normal mucosa of cancer or noncancer patients with regards to the CRABP concentration. The absence of CRABP in the cancer tissue was not dependent on the degree of differentiation. These results indicate that the CRABP disappears when the normal mucosa becomes malignant. If such a change is also demonstrated in known premalignant conditions of the esophagus, CRABP could serve as a diagnostic biochemical marker for early detection of this cancer.

Immunohistological localization of alpha 1-microglobulin in normal rat tissues

The tissue distribution of rat alpha 1-microglobulin (alpha 1-m) was studied by indirect immunofluorescence in various rat tissues using a polyvalent rabbit antiserum to the purified antigen and a monoclonal antibody (H23) to the human homologue, in parallel with a polyclonal anti-rat IgA antiserum. It was found that all tissues stained by anti-IgA were also alpha 1-m positive; these tissues included tissues of the stomach, duodenum, ileum, colon, pancreas, trachea, esophagus and jejunum. However, the observation that IgA plasma cells as well as secretory cells, while positively stained by anti-IgA, are alpha 1-m negative suggests that the association between IgA and alpha 1-m occurs at a postsecretory stage, after the IgA molecules have been transported across the epithelial cells. Additionally, hepatocytes were intensely stained by anti-alpha 1-m antibodies, indicating that the liver, as already suggested by metabolic studies on isolated guinea-pig liver explants, may be responsible for the synthesis of this protein. Among lymphoid tissues, an intense and homogeneous staining was observed in the thymus and the white pulp of the spleen. Sections of lymph nodes, however, showed differential staining; apart from a few isolated dendritic cells in the mantle region of the lymphoid follicles, the germinal centers and medullary cords showed no staining with anti-alpha 1-m antibodies. The paracortical cells, macrophages in the subcapsular sinus, and interfollicular lymphocytes showed intense cytoplasmic staining with anti-alpha 1-m antibodies. In other tissues, macrophages, monocytes, tissue histiocytes, and dendritic cells were alpha 1-m positive. Although they confirm the presence of alpha 1-m in the lymphoid tissues, as already reported in man, these results show that the protein is also present in hepatocytes and in exocrine fluids containing IgA. Since alpha 1-m, like secretory component, can bind to IgA to form stable complexes, these two heavily glycosylated proteins may have similar biologic properties.

Unusual histological appearances of barium sulphate--a case report with scanning electron microscopy and energy dispersive x ray analysis

Multiple birefringent rhomboidal crystals seen on histological examination of a resected oesophagus were subsequently found to contain elemental barium and sulphur on energy dispersive x ray ( EDX ) analysis. Scanning electron microscopy and EDX analysis of readily available commercial barium sulphate suspensions suggested that the two forms of barium sulphate previously described in tissue sections may be a result of the method of preparation of the commercial suspension used. With increased use of barium sulphate prepared by crushing the natural compound, birefringent rhomboidal crystals should be found with increasing frequency in endoscopic biopsy samples and resected specimens.

The occurrence of serotonin-containing cells in the esophageal epithelium of the bullfrog Rana catesbeiana: a fluorescence histochemical and immunohistochemical study

Fluorescence histochemical examination of biogenic amines of the frog esophageal mucosa revealed that a serotonin-like monoamine exhibiting an yellow fluorescence was present in a certain type of cells. The new type of cells was specifically stained by the immunohistochemical method using anti-serotonin antiserum. From these observations, it is suggested that the new cell type in the esophageal mucosa probably contains 5-hydroxytryptamine (serotonin). The serotonin-containing cells were argentaffin, but negative for Grimelius' silver stain.

A histochemical method suitable to discriminate free cholesterol from its esters and both from 7-dehydrocholesterol and vitamins D

The peracetic acid-toluidine blue and the peracetic acid-Schiff reactions as well as the failure of HgCl2-formalin fixative for inhibiting these reactions appears as a very useful method for free cholesterol histochemical detection and to discriminate it from its esters and from some of its metabolic products such as 7-dehydrocholesterol and vitamins D. The cholesterol histochemical detection provided by those reactions appears specific taking into account the findings afforded by spot tests. The peracetic acid-toluidine blue reaction is very suitable for histochemical purposes on tissue sections, since it does not produces tissues damages, it is sensitive and the stained end product is almost insoluble in the solvents frequently used in histological techniques. The previous ribonuclease treatment and methylation are very useful in avoiding the basophil substances interference on the peracetic acid-toluidine blue reaction. The 2,4-dinitrophenylhydrazine carbonyl group blockade is useful to decrease the influence of carbonyl group on the peracetic acid-histological techniques. The previous ribonuclease treatment and methylation are very useful in avoiding the basophil substances interference on the peracetic acid-toluidine blue reaction. The 2,4-dinitrophenylhydrazine carbonyl group blockade is useful to decrease the influence of carbonyl group on the peracetic acid-histological techniques. The previous ribonuclease treatment and methylation are very useful in avoiding the basophil substances interference on the peracetic acid-toluidine blue reaction. The 2,4-dinitrophenylhydrazine carbonyl group blockade is useful to decrease the influence of carbonyl group on the peracetic acid-Schiff reaction. The peracetic acid-toluidine blue reaction is more sensitive and more specific than peracetic acid-Schiff reaction, since the tissues do contain Schiff reactive products unable to be 2,4-dinitrophenylhydrazine blocked which interfere on the results of the latter reaction decreasing its specificity and its sensitivity. The cholesterol histochemical detection based on the peracetic acid-toluidine blue and peracetic acid-Schiff reaction as it is suitable in discriminating free cholesterol from its esters as well as from some of its metabolic products it appears very useful for metabolic studies on tissue sections.

Tissue-specific expression of keratin proteins in human esophageal and epidermal epithelium and their cultured keratinocytes

In contrast to the simplified keratin content of bovine, rabbit, and rat esophageal epithelium (composed mainly of a 57 and 46 or 51 kD keratin, depending on the animal species), human esophageal epithelium contained a quantitatively different array of keratin proteins, ranging in molecular weight from 37 to 61 kD. The pattern of keratin proteins from human esophageal epithelium differed qualitatively and quantitatively from that of human epidermis. Human esophageal epithelium lacked the 63, 65, and 67 kD keratins characteristic of human epidermis, consistent with the absence of a granular layer and an anucleate stratum corneum. Moreover, human esophageal epithelium contained a distinctive 61 kD keratin protein which was either not present or present in only small amounts in human epidermis and variable amounts of a 37 kD keratin. Whereas the 56, 59, and 67 kD keratins were the most abundant keratins in human epidermis, the 52, 57, and 61 kD keratins predominated in human esophageal epithelium. During in vitro cultivation, both human epidermal and esophageal keratinocytes produce colonies which are stratified, but the morphologic appearance of these cultured epithelia differs. Only cultured human epidermal keratinocytes contain keratohyalin granules in the outermost layers and a prominent 67 kD keratin on immunoprecipitation. Otherwise the keratin contents appear similar. In conclusion, human esophageal epithelium exhibited intertissue and interspecies differences in the pattern of keratin proteins. During in vitro cultivation, human esophageal keratinocytes retained some aspects of their distinctive program of differentiation.

Autoradiographic demonstration of estrogen receptors in the esophagus of baboons

Previous reports have indicated that certain sex steroids are intimately involved in the physiologic activities of the gastrointestinal tract. We performed autoradiographic studies using [3H]estradiol and [3H]dihydrotestosterone on male and female baboons for the purpose of identifying estrogen or androgen receptors, or both, in the lower and midregions of the esophagus. Discrete sites of localization of exposed photographic emulsion were observed over nuclei of skeletal muscle and interstitial cells of male baboons injected with the estrogen. No localization of receptors was observed in these same cells in females given estrogen nor in any male and females injected with the androgen. These observations suggest that skeletal muscle and interstitial cells of the male baboon contain specific high-affinity estrogen receptors that might have a direct effect on the skeletal muscle cells and may modulate their cellular activities.

Distribution of surfactants in the canine gastrointestinal tract and their ability to lubricate

Surface-active phospholipids, chemically similar to pulmonary surfactants, have been identified by thin-layer chromatography in gastric juice and on the mucosal lining of five tissues along the canine gastrointestinal tract. These included esophagus, oxyntic tissue, midduodenum, midjenunum, and midcolon. The mucosal phospholipid composition did not change appreciably along the length of the gastrointestinal tract, with the most prominent species being phosphatidylcholine (PC) (34-45%) and phosphatidylethanolamine (PE) (18-32%). The gastrointestinal mucosal surface also contained lesser amounts (5-10% each) of sphingomyelin (Sp), lysophosphatidylcholine, phosphatidylinositol (PI), and phosphatidylserine (PS) and small but detectable quantities of phosphatidylglycerol (PG) and phosphatidic acid. Both the lipid extracts of all six gastrointestinal sources as well as commercially available phospholipids identified in these samples (PC, Sp, PE, PI, PS, and PG) proved to be good boundary lubricants. Each reduced the coefficient of friction by greater than 75% between glass and carboxylated yarn when tested by a standard method for evaluating textile "sizes." The results are discussed in relation to the possible role of the surface-active molecules in imparting properties conducive to lubrication and acid protection onto the gastrointestinal epithelium.

Glycogenic acanthosis of the esophagus

A nodular appearance of the esophageal mucosa was observed in 28.3% of 300 consecutive double-contrast esophagrams. This most commonly appeared as numerous uniformly sized, usually less than 3 mm, subtle, round elevations involving the entire esophageal surface. When carefully performed, endoscopy will almost always confirm these findings. Endoscopic biopsies performed in 10 patients demonstrated the nodules to represent glycogenic acanthosis--a combination of cellular hyperplasia and increased cellular glycogen. The radiographic appearance of these nodules, while usually characteristic, may vary and they may simulate pathologic processes, particularly moniliasis. Distinction can usually be made by clinical and radiologic criteria. Although the etiology is unknown, this seems to be of no clinical significance.

Silica fragments from millet bran in mucosa surrounding oesophageal tumours in patients in northern China

Millet bran is a component of the diet in the area of highest oesophageal cancer incidence in northern China. Millet bran was found to contain up to 20% by weight of silica; some of this silica occurs as friable sheets or sharply-pointed fibres. These types of silica in millet bran are the most likely source of an unusual contamination with fragments of silica found in the oesophageal mucosa surrounding tumours in patients in northern China. A group of mucosal samples analysed together contained over 5,000 particles/g (100 parts per million by weight), ten times as many as were found in tissue from normal controls taken at necropsy in London. The modal diameter was 10 microgram (1-70 microgram). The particles were in the body of the mucosa and were not simply a surface contaminant. Silica fragments and fibres of similar size originating from other plant species occur in the diet in the two other regions of greatest incidence of oesophageal cancer, the Transkei and Iran. If such fragments enter the mucosa, they must cause some degree of trauma, and they may also be able to stimulate proliferation by providing anchorage. These findings suggest the possibility that silica particles might be involved in the aetiology of oesophageal cancer.

Active trypsin and reflux oesophagitis: an experimental study in rats

In order to clarify the role of active trypsin, bile acids and pepsin in reflux oesophagitis, a comparable series of experiments was performed in rats before and after reflux-inducing operations. Three control procedures were used--laparotomy (n = 10), oesophageal transection and reanastamosis (n = 7) and a Roux-en-Y reconstruction (n = 9)--and seven experimental procedures in order to produce gastric, bile and pancreatic reflux (G + B + P) (n = 9), gastric and pancreatic reflux (B + B) (n = 8), bile and pancreatic reflux (B + P) (n = 10), pancreatic reflux alone (P) (n = 9), gastric reflux alone (G) (n = 8), bile reflux alone (B) (n = 9) and gastric with bile reflux (G + B) (n = 9). Macroscopic and histologically confirmed oesophagitis was produced in groups G + B + P, G + P, B + P and P. The trypsin levels were significantly elevated in these groups, compared to both the control and other experimental groups (P less than 0.01). Bile acid levels were insignificantly different between the groups. Because these experiments involved vagal transection, no oesophagitis was found in the gastric juice reflux group. This study has shown for the first time a correlation between the presence of active trypsin in the oesophagus and the occurrence of oesophagitis. It is possible that active components of duodenal juice may contribute to the development of reflux oesophagitis in man.

Differences in sulfated glycosaminoglycans composition of the gastrointestinal mucosa

Sulfated glycosaminoglycan (SGAG) composition of normal mucosa of esophagus, gastric body, antrum, duodenum, jejunum and rectum is reported. Each region examined may be defined by specific sulfated glycosaminoglycan distributions showing variations in relative proportions and total amount of heparan sulfate, dermatan sulfate and chondroitin 4, 6-sulfate. The results are discussed in the light of a recent proposal regarding the role of these compounds in cell-cell recognition and stimulation of cell division. The methodology made it possible to detect sulfated glycosaminoglycans from small amounts of tissue obtained by endoscopic biopsies.

Isolation and characterization of two polypeptides that form intermediate filaments in bovine esophageal epithelium

Cells in the stratified squamous epithelium of bovine esophagus contain abundant tonofilaments measuring 6-10 nm in diameter. Two polypeptides, extracted from esophageal epithelium with 0.05 M Tris, pH 7.4, containing 8 M urea and 25 mM beta-mercaptoethanol, comprise 35% of the total extractable protein. These polypeptides have apparent molecular weights of 46,000 and 56,000 daltons and are rich in glutamic acid-glutamine, glycine, and serine. Each polypeptide can be partially purified by DEAE-cellulose chromatography. Mixtures of the purified polypeptides from filaments in vitro that measured 6-10 nm in diameter. Neither polypeptide formed filaments by itself. Filaments formed in vitro give an alpha-keratin type x-ray diffraction pattern.. These data indicate that the tonofilaments in esophageal epithelium are formed primarily from these two polypeptides.

A technique to tocopherol (vitamin E) histochemical detection

A technique to detect tocopherol histochemically was proposed in basis on the following schedule: 1. toluidine blue and Schiff reagent negativity before a suitable oxidation; 2. performic acid-toluidine blue and performic acid-Schiff reagent positivity after fixing in formalin-CaCl2; 3. performic acid-toluidine blue and performic acid-Schiff reagent negativity after fixing in formalin-HgCl2; 4. ferric ferricyanide reaction positivity not influenced by the formalin-HgCl2 blockade. This technique tested on filter paper strips loaded with several lipids, steroids, vitamins, proteins, amino acids and ribonucleic acid shows that it is specific to tocopherols among the tested substances. Used on tissue sections this technique appears as very suitable to histochemical purposes.

The distribution and cellular origin of vasoactive intestinal polypeptide in the avian gastrointestinal tract and pancreas

The distribution and origins of vasoactive intestinal peptide (VIP) in the gut and pancreas of the turkey were studied by radioimmunoassay of tissue extracts and by immunocytochemistry. Several antisera were used that vary in their specificity for different regions of porcine or chicken VIP. Radioimmunoassays using NH2-terminal specific antisera that react almost equally with porcine and chicken VIP's revealed signficant amounts of immunoreactive VIP in extracts of pancreas, brain and all regions of the gastrointestinal tract from crop to colon. Highest concentrations (300 pmol/g) were found in the colon muscle, and concentrations were generally low (< 20 pmol/g) in the mucosal layers of the small intestine. After ion exchange chromatography of extracts on CM-Sephadex three immunoreactive forms of VIP were separated corresponding to the three molecular forms previously found in mammalian gut extracts. In immunocytochemical studies nerve fibres were found throughout the gut, and in the pancreas. Immunoreactive nerve cell bodies were also identified in the submucous plexus throughout the gut, but were particularly prominent in the oesophagus and pancreas. It has previously been shown that VIP is a strong stimulant of the flow of pancreatic juice in birds whereas the structurally related hormone secretion, which is known to control the flow of pancreatic juice in mammals, is a weak stimulant. It is proposed that in birds VIP might regulate the pancreas, and other aspects of gut function, as a neurotransmitter or neurohormone.

The influence of a high-bran diet on trace element retention in primates

Proton-induced x-ray emission (PIXE) has become an established analytical method for the determination of trace elements in biomedical samples. The standard PIXE technique has been modified, resulting in a considerable improvement in detection limits. Refinements include the use of an external proton beam, the incorporation of a triggered beam-pulsing system, and the backward angle location (135 degrees to the incident ions) of the Si(Li) x-ray detector. The technique is now clearly capable of rapid, multielemental investigations, and requires a minimum of target preparation. Samples of liver and oesophagus tissue were obtained from 26 baboons at autopsy. Of these, 13 had been maintained on a semi-synthetic (high-bran) diet, with the remaining 13 forming the control group. Some 15 elements were analysed quantitatively; optimum detection limits were in the range 10-20 PPB (1 billion = 10(9). Clear differences were obtained: the high-bran diet is shown to produce imbalances in biologically active elements such as S, K, Ca, Ni Cu and Zn. These results are discussed on the basis of the phytate hypothesis, in terms of which trace elements in the diet are rendered physiologically unavailable to the subject.

[Esophagogastric junction in the dog. Study of some pHmetric technics]

The authors' carried out a pHmetric study of stomach, esophagus and gastroesophageal junction in dog, using four techniques: intermittent pull-through technique, continuous pull-through technique, continuous push-through technique and rapid pull-through technique. The study was done in six adult male dogs. Each animal was studied in five sessions, having been undergone 16 examinations and having been done 4 examinations of each technique. The intermittent pull-through technique (TPI) proved to be the most adequate for the pHmetric study, because it propitiates better interaction conditions between electrode and environment. Of the techniques of continuous dislocation, the continuous push-through technique (TEC) presented the most satisfactory results, having the electrode presented little latency. The continuous pull-through technique (TPC) has its application on the dependence of the pull speed; it was observed that the less the speed the less the latency of the electrode. The rapid pull-through technique (TPCR) doesn't permit an adequate interaction between electrode-environment, in consideration of the rapidity of the examination.

Demonstration of sulfhydryl and disulfide groups by a fluorescent maleimide procedure

Several fluorescent maleimide compounds were evaluated as possible substitutes for N-(4-aminophenyl)maleimide in the histochemical procedures developed by Sippel (1973, 1978a, b, 1980) for the demonstration of sulfhydryl and disulfide groups. The brightest and most selective fluorescence was obtained by using N-(7-dimethylamino-4-methylcoumarinyl)maleimide (DACM), although both eosin-5-maleimide and fluorescein-5-maleimide could also be used if adequate control preparations were made.