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C E Rubin

Publications and source records attributed to C E Rubin.

At least 37 records · Page 2Linked to original sources

Specialized metaplastic columnar epithelium in Barrett's esophagus. A comparative transmission electron microscopic study.

Barrett's esophagus develops as a complication of regurgitant esophagitis and predisposes patients to the development of dysplasia and esophageal adenocarcinoma. Prior ultrastructural studies have suggested that Barrett's epithelium is a mucous secretory epithelium that shares some morphologic features with the intestine. The origin and development of Barrett's epithelium and the cellular abnormalities accompanying its neoplastic progression are poorly understood. In an attempt to better understand the histogenesis of the mucus-producing cells that predominate in Barrett's epithelium, these cells were studied by transmission electron microscopy and compared with other upper gastrointestinal epithelia: esophageal glands, normal gastric surface, pit, and cardiac gland regions, gastric intestinal metaplasia, and normal jejunal villous tip and crypt regions. A total of 134 mucosal biopsies from the stomach and esophagus of 28 patients with Barrett's esophagus and 37 biopsies from 14 other control patients were studied. Barrett's specialized metaplastic surface cells display a spectrum of ultrastructural features among three main surface columnar epithelial cell types: mucous cells resembling those seen in the normal gastric surface epithelium or resembling mucous neck cells normally seen in the gastric pits; goblet cells similar to those seen in the jejunum; and "pseudoabsorptive" cells with features of both gastric mucous secretory cells and jejunal absorptive cells. Cytoplasmic organelles of Barrett's specialized metaplastic, normal gastric mucous neck, and normal gastric surface mucous epithelial cells, including rough endoplasmic reticulum, glycogen aggregates, Golgi apparatus, and mucous secretory granules, have common ultrastructural features associated with mucus synthesis. The morphologic heterogeneity of Barrett's specialized metaplastic cells and common ultrastructural features associated with normal mucus biosynthesis suggest that they develop from a gastrointestinal stem cell that retains the capacity for a wide range of normal and abnormal differentiation in the esophagus. The identity of this undifferentiated cell, which may reside in normal proximal gastric or esophageal mucosa, remains unknown. However, the gastric mucous neck cell has properties that suggest it could be the progenitor cell for Barrett's esophagus because it is a stem cell that has ultrastructural similarities to Barrett's specialized metaplastic epithelial cells and it is located in intact gastric mucosa adjacent to where Barrett's esophagus forms.

Adult↗

Diffuse excess mucosal collagen in rectal biopsies facilitates differential diagnosis of solitary rectal ulcer syndrome from other inflammatory bowel diseases.

Solitary rectal ulcer syndrome (SRUS) is sufficiently uncommon that the clinician or general pathologist may lack familiarity with the disorder and may confuse it with other inflammatory bowel diseases. To evaluate the role of collagen staining in facilitating the differential diagnosis of SRUS, an initial open review was undertaken on 1672 consecutive patients whose 4780 colorectal biopsies were stained with H&E with added saffron to demonstrate collagen. Excess mucosal collagen was present in 39 (2.3%) of these patients. Twenty patients with a diffuse excess of mucosal collagen in biopsies from rectal ulcer margins or from otherwise abnormal rectal mucosa had SRUS; in the remaining 19 patients, excess mucosal collagen was focal (seven ischemic colitis, five collagenous colitis, three adenocarcinoma, and four chronic idiopathic ulcerative colitis). Diffuse excess mucosal collagen never was seen in idiopathic inflammatory bowel disease (128 Crohn's colitis and 446 ulcerative colitis). Blinded reviews then were performed on rectal biopsies from 33 patients with a variety of diagnoses (14 SRUS and 19 controls). Diffuse excess collagen by saffron staining was consistently observed in SRUS but was absent in all 19 controls. Additional blinded reviews were carried out because the collagen staining pattern in ischemic colitis, although focal, could potentially be confused with SRUS. It was possible to differentiate these two diseases blindly from one another by using additional histologic criteria (14 SRUS and 12 ischemic colitis). We conclude that the demonstration of a diffuse excess of mucosal collagen in rectal biopsies facilitates the diagnosis of SRUS and differentiates it from idiopathic ulcerative colitis and Crohn's disease, with which SRUS is often confused, and other inflammatory bowl diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗

Blocking action of parenteral desferrioxamine on iron absorption in rodents and men.

Desferrioxamine (DFO) is an iron chelating agent that, when administered orally, interferes with gut absorption of inorganic iron and, when administered parenterally, binds body iron and is excreted as ferrioxamine in bile and urine. Studies were carried out in normal and iron-deficient male rats and in normal, iron-replete male volunteers to investigate the blocking action of parenteral DFO on the absorption of radioiron. Radiolabeled ferrous ammonium sulfate, transferrin iron, or hemoglobin iron was injected directly into the jejunum of rats with or without intramuscular injections of DFO. Radioiron administered as ferrous sulfate or as transferrin iron was given to the volunteers by mouth or by direct duodenal infusion, respectively, with or without intravenous infusions of DFO. In iron-deficient rats, intramuscular DFO injections commencing 1 h before direct jejunal injection of radioiron significantly blocked absorption of inorganic iron (26% with DFO, 64% without DFO), transferrin iron (4% with DFO, 69% without DFO), and hemoglobin iron (3% with DFO, 19% without DFO). In normal rats, DFO injections also significantly blocked absorption of inorganic iron and transferrin iron. In normal volunteers, intravenous DFO infusions commencing 1 h before administration of radioiron significantly blocked absorption of physiologic doses of inorganic iron (3% with DFO, 21% without DFO) and transferrin iron (1% with DFO, 20% without DFO). The quantity of radioiron excreted in urine by both rats and humans with administration of DFO did not account for the observed decrement in absorption of radioiron. Biochemical analysis of rat intestinal mucosal scrapings after injection of DFO and administration of radioiron demonstrated the accumulation of a small molecular weight fraction containing iron that was ferrioxamine (iron-chelate) complex. We conclude that parenterally administered DFO can enter the small intestinal mucosa, bind intracellular iron, and block iron absorption. Parenteral DFO blocks the absorption of inorganic iron, transferrin iron, and hemoglobin iron, suggesting that all three iron species enter a common chelatable pool within the small intestinal mucosa and may share a common pathway of absorption.

Adult↗

Endoscopic biopsy can detect high-grade dysplasia or early adenocarcinoma in Barrett's esophagus without grossly recognizable neoplastic lesions.

There is uncertainty regarding the value of endoscopic biopsy surveillance in Barrett's esophagus because, in retrospective studies, some patients with high-grade dysplasia in endoscopic biopsy specimens have had unexpected advanced adenocarcinoma discovered at the time of esophageal resection. We compared the accuracy of preoperative endoscopic biopsy diagnoses with the final pathologic diagnoses in esophagectomy specimens in 4 patients who had both high-grade dysplasia and intramucosal carcinoma and 4 other patients who had only high-grade dysplasia preoperatively. The histologic lesions in all 8 patients were documented in intact mucosa with no gross evidence of neoplasia by endoscopy. The preoperative diagnoses were defined with an endoscopic biopsy protocol in which specimens were taken with large-channel biopsy forceps at least every 2 cm throughout the length of Barrett's epithelium. Final pathologic diagnoses derived from detailed analysis of the resected specimens confirmed high-grade dysplasia without carcinoma in 4 patients and intramucosal carcinoma in 2 patients. The remaining 2 patients with a preoperative diagnosis of intramucosal carcinoma had focal submucosal invasion by carcinoma in the resected specimens, but no involvement of the muscularis propria or adventitial lymph nodes. Because the natural history of high-grade dysplasia is not known, the decision to operate on patients with this lesion must be carefully weighed and individualized for each patient. Two of our patients who underwent esophageal resection for high-grade dysplasia without cancer died, one immediately postoperatively and the other 9 mo later after a postoperative stroke. Once intramucosal carcinoma is documented, surgery should be considered if the patient is an acceptable operative risk. We conclude that systematic preoperative endoscopic biopsy of intact mucosa in Barrett's esophagus can correctly detect high-grade dysplasia, either alone or in combination with early, treatable adenocarcinoma.

Adenocarcinoma↗

Comparison of human jejunal and ileal fat absorption by electron microscopy.

Morphologic and physiologic experiments in rodents have demonstrated differences between jejunal and ileal fat absorption. Compared with the rat jejunum, absorbed lipid particles within rat ileal absorptive cells are larger and exit at a slower rate. To evaluate the relevance of these observations to humans, we studied jejunal and ileal ultrastructure in 3 volunteers, each of whom had an intact small intestine and an ileostomy postcolectomy for ulcerative colitis. Proximal jejunal biopsy specimens were obtained via a hydraulic tube after an overnight fast and again after a 20-min intrajejunal lipid infusion. On a separate day, terminal ileal biopsy specimens were taken via the stoma with a small steerable suction biopsy tube after an overnight fast and again after a 20-min intraileal infusion of the same lipid mixture. One volunteer underwent biopsy after a 60-min ileal infusion of a digested meal of higher lipid content. Electron microscopy of fasting human jejunal absorptive cells revealed obvious smooth endoplasmic reticulum in the extreme apical region beneath the terminal web; very low density lipoprotein particles were observed within smooth endoplasmic reticulum and Golgi cisternae. In contrast, fasting human ileal absorptive cells contained less apical smooth endoplasmic reticulum and fewer or no very low density lipoprotein particles. After the 20-min infusion of lower-lipid content, human jejunal and ileal absorptive cells were indistinguishable because they contained fat particles of the same size and number within smooth endoplasmic reticulum, Golgi cisternae, and extracellular spaces. After the 60-min ileal infusion of higher-lipid content, human ileal absorptive cells appeared to be the same as those of the human jejunum after similar lipid infusions. Our observations of the ultrastructural similarity in human jejunal and ileal absorptive cells after lipid infusions contrasts with those in rodents and may reflect species-specific differences in mechanisms of fat absorption.

Adult↗

Observer variation in the diagnosis of dysplasia in Barrett's esophagus.

The potential value of biopsy surveillance of patients with Barrett's esophagus for dysplasia is diminished by a lack of agreement on the diagnostic criteria for dysplasia. In a preliminary consensus conference, experienced gastrointestinal pathologists from four medical centers agreed on criteria for a five-tiered histologic classification of dysplasia in Barrett's esophagus--negative for dysplasia, indefinite for dysplasia, low-grade dysplasia, high-grade dysplasia, and intramucosal carcinoma. Eight morphologists in the four centers tested the criteria for interobserver agreement by examining a set of coded slides that had been chosen to include some especially difficult interpretative problems in all five histologic classifications. Interobserver agreement of 85 and 87% was achieved in successive reviews when the combined group of high-grade dysplasia and intramucosal carcinoma was compared with the combined group of low-grade dysplasia, indefinite for dysplasia, and negative for dysplasia. Comparison of other groups yielded less agreement. For example, negative for dysplasia could be distinguished from all other diagnoses with an interobserver agreement of 72%. We conclude that experienced gastrointestinal morphologists can diagnose high-grade dysplasia and intramucosal carcinoma with a high degree of agreement and thus can detect those patients who may need immediate rebiopsy or esophageal resection. Either further refinement of histologic criteria or alternate diagnostic methods will be needed to achieve the reproducible diagnosis of indefinite changes and low-grade dysplasia. This is important because patients with such changes theoretically merit closer endoscopic surveillance.

Barrett Esophagus↗

Barrett's esophagus. Correlation between mucin histochemistry, flow cytometry, and histologic diagnosis for predicting increased cancer risk.

A predominance of sulfated mucin in the nongoblet columnar cells of Barrett's specialized metaplastic epithelium has been postulated to be a form of mild dysplasia and to indicate an increased risk of adenocarcinoma. Flow cytometry for the analysis of nuclear DNA content and cell cycle parameters has also been postulated to be an objective aid in the diagnosis of dysplasia and carcinoma in Barrett's esophagus. The authors investigated the relationship among sulfated mucin, flow cytometric data, and histologic diagnosis in each of 152 biopsies from 42 patients who had Barrett's specialized metaplastic epithelium. Sulfated mucin, as detected by the high iron diamine-Alcian blue stain, was present in biopsies from 8 of 11 (73%) patients with the histologic diagnosis of dysplasia or carcinoma, in 7 of 9 (78%) patients whose biopsies were indefinite for dysplasia, and in 12 of 22 (55%) patients whose biopsies were negative for dysplasia (P = 0.37). Sulfated mucins predominated in 9%, 22%, and 9% of the patients, respectively (P = 0.56). Abnormal flow cytometry (aneuploidy or increased G2/tetraploid fraction) was found in all patients with the histologic diagnosis of dysplasia or carcinoma, in 3 of 9 (33%) indefinite for dysplasia, and in 1 of 22 (5%) negative for dysplasia (P = less than 0.0001). Neither the presence nor the predominance of sulfated mucin in the specialized metaplastic epithelium of Barrett's esophagus has sufficiently high sensitivity or specificity for dysplasia or carcinoma to be of value in managing patients. Abnormal flow cytometry shows excellent correlation with the histologic diagnosis of dysplasia and carcinoma; it detects a subset of patients whose biopsies are histologically indefinite or negative for dysplasia, but who have flow cytometric abnormalities similar to those otherwise seen only in dysplasia and carcinoma.

Barrett Esophagus↗

Barrett's esophagus. Correlation between flow cytometry and histology in detection of patients at risk for adenocarcinoma.

The value of endoscopic surveillance biopsy for dysplasia and carcinoma in patients with Barrett's esophagus is controversial. One reason is that the available histologic criteria are not adequate to separate patients with lesser degrees of dysplasia or predysplastic changes who are at increased risk for carcinoma and therefore require more frequent surveillance from those patients who are not at increased risk. We used flow cytometry and histology to evaluate 317 biopsy specimens from 64 consecutive patients who were in a cancer surveillance program for Barrett's esophagus and 3 additional patients with adenocarcinoma in Barrett's esophagus. Specimens from 10 patients had aneuploid cells; 9 of these had dysplasia or carcinoma, or both, but 1 patient had only specialized metaplastic epithelium. Twenty specimens ahd G2/tetraploid fractions greater than 6%; all 20 came from patients who had cancer or dysplasia, or were indefinite for dysplasia. All patients with dysplasia or adenocarcinoma had evidence of genomic instability (aneuploidy) or abnormalities of mucosal proliferation by flow cytometry, even when the dysplasia was focal or difficult to recognize histologically. In a small subset of patients with specialized metaplastic epithelium whose specimens were histologically negative or indefinite for dysplasia, the mucosa had aneuploid cell populations or proliferative abnormalities that were otherwise found only in dysplasia or carcinoma. Additional study may prove that this subset of patients merits more frequent endoscopic biopsy surveillance because of an increased risk for developing carcinoma. Because the abnormalities we have detected by flow cytometry correlate well with the conventional histologic diagnoses of dysplasia and carcinoma, they may prove to be a valuable objective adjunct in the diagnosis of dysplasia and carcinoma in Barrett's esophagus.

Adenocarcinoma↗

A double-blind, cross-over, study of oral N-acetylcysteine in Sjögren's syndrome.

Twenty-six patients with primary or secondary Sjögren's syndrome were treated in a double-blind, cross-over trial for a four week period with oral N-Acetylcysteine and placebo. Before treatment there were significantly elevated salivary lactoferrin levels in the patients when compared to 51 healthy controls (p = 0.0005), and significantly decreased levels of tear lysozyme when compared to 24 controls (p = 0.0003). Salivary sodium, potassium, inorganic phosphate, amylase and immunoglobulin G, A or M levels were not significantly different from control values. After treatment with N-Acetylcysteine, Sjögren's syndrome patients reported improvements in ocular soreness (p = 0.004), ocular irritability (p = 0.006), halitosis (p = 0.033) and daytime thirst (p = 0.033). N-Acetylcysteine, but not placebo improved the van Bijsterveld score (p = 0.026), but neither agent improved the Schirmer test, the tear break up time or any of the laboratory tests. These results suggest that N-Acetylcysteine may have a true therapeutic effect on the ocular symptoms of Sjögren's syndrome and be worthy of a longer study.

Acetylcysteine↗

Reversal of dementia associated with Whipple's disease by trimethoprim-sulfamethoxazole, drugs that penetrate the blood-brain barrier.

A previously healthy 67-yr-old man presented with progressive dementia over an 11-mo period. Evaluation revealed evidence of malabsorption. Jejunal biopsy established the diagnosis of Whipple's disease. No other etiology for the patient's dementia was uncovered. Treatment with trimethoprim-sulfamethoxazole resulted in rapid elimination of Whipple's bacilli from the jejunum and complete reversal of the patient's dementia over a 6-mo period. Significant levels of trimethoprim and sulfamethoxazole were easily quantitated in the cerebrospinal fluid during therapy. There is increasing recognition of progressive neurologic disease in patients with Whipple's disease who were treated with tetracycline. The reversal of presumed central nervous system disease in this case suggests that drugs that penetrate the blood-brain barrier might be preferable for the initial treatment of Whipple's disease.

Aged↗

Ultrastructural immunolocalization of apolipoprotein B within human jejunal absorptive cells.

Apolipoprotein B (apoB) was localized by electron microscopy within absorptive cells of human jejunal biopsy specimens taken fasting and after micellar fat infusion. Nakane's double antibody immunoperoxidase technique was used to label apoB near open cut surfaces of 60-Micrometers fixed tissue slices sectioned by a Ralph knife in a Vibratome. In fasting tissue, apoB label was found within structurally intact peri-mitochondrial rough endoplasmic reticulum (RER) and within Golgi cisternae of absorptive cells covering the tips of jejunal villi. After fat infusion, apoB label was found adjacent to very low density lipoproteins (VLDL) and chylomicrons within apical smooth endoplasmic reticulum (SER). Less label was seen within RER than in fasting absorptive cells, and RER-SER connections containing apoB label were occasionally seen. Expanded Golgi vesicles and cisternae contained VLDL, chylomicrons, and apoB label. Vesicles containing chylomicrons and apoB label were occasionally visualized bordering the lateral plasma membrane in a configuration suggesting exocytosis. Specific apoB label was regularly seen within intercellular spaces and capillaries, but the in vivo significance of this Localization was problematical. These observations suggest that apoB is synthesized in RER, transfers to SER where it is incorporated into new VLDL and chylomicrons, and moves to Golgi cisternae and vesicles to be prepared for exocytosis through the plasma membrane.

Apolipoproteins↗

Linolenate transport by human jejunum: presumptive evidence for portal transport at low absorption rates.

Are the small quantities of linolenic acid (LA) in a meal absorbed via a different pathway than the higher concentrations of the other long-chain fatty acids (LCFA) in a mixed meal? To answer this question, varying LA concentrations were infused into the human jejunum via a quadruple-lumen hydraulic biopsy tube. After 0.01-mM LA infusion, no LA was found in triglyceride (TG) extracted from jejunal biopsies, although 58% of the phospholipid plus monoglyceride fraction (PL + MG) and 42% of the LCFA fraction were LA. In marked contrast, after 5.0-mM LA infusion, 60% of the TG, 28% of the PL + MG, and only 3% of the LCFA fractions were LA. By electron microscopy, mostly very low-density lipoprotein-sized (less than 750 A) particles were seen within jejunal fasting biopsies and in biopsies after 0.01, 0.1, or 1.0-mM LA infusions; mostly chylomicrons (greater than 750 A) were seen within jejunal biopsies after 5.0-mM LA infusion. We conclude that LA at its usual very low dietary concentrations is absorbed mostly as invisible LCFA and PL molecules; whereas at higher concentrations it is absorbed like most dietary fat via lacteals as TG and PL within visible chylomicrons.

Biological Transport↗

Rectal biopsy in the diagnosis of Crohn's disease: value of multiple biopsies and serial sectioning.

We performed a retrospective evaluation of 243 rectal biopsies from 90 patients who eventually had Crohn's disease proven clinically or by surgery. A portion of each rectal biopsy was serially sectioned. Twenty-five of the 90 patients (28%) had epithelioid granulomas. Half of these patients had an epithelioid granuloma in only one of two or more biopsies. Sixteen percent of these granulomas were so small as to be seen in only six or less successive serial 4-microM sections. This high yield of granulomas is probably attributable to the examination of at least 90 serial sections, usually from each of two rectal biopsies per patient. Using partial serial sectioning, epithelioid granulomas were found almost as frequently in grossly normal as in grossly abnormal appearing mucosa. No granulomas were seen in suitable controls including normals and patients with ulcerative colitis or other diseases. When the differential diagnosis between idiopathic ulcerative colitis and Crohn's disease is uncertain, we recommend taking two rectal biopsies and serially sectioning part of each.

Adolescent↗

Evaluation of electrofulguration in control of bleeding of experimental gastric ulcers.

The safety and efficacy of electrofulguration for control of bleeding from standard canine experimental gastric ulcers was studied. At settings of 2, 5, and 8 on a Valleylab SSE-3 generator, 0.5-sec applications provided effective hemostasis. However, a setting of 2 required an excessive number of applications. Settings of 5 and 8 showed deep injury to the muscularis externa when examined histologically. In an attempt to reduce the depth of injury, a more easily ionizable gas mixture of 50% argon gas and 50% CO2 was compared to CO2 alone. At a generator setting of 5 with 0.5-sec applications the argon-CO2 mixture produced slightly less deep injury than CO2 alone, but the difference was not significant. Although electrofulguration was effective in stopping bleeding in these experiments, the tissue injury was unpredictable and deep.

Animals↗

Argon vs. neodymium YAG laser photocoagulation of experimental canine gastric ulcers.

A neodymium YAG (Nd:YAG) laser was evaluated in a dog ulcer model used in the same manner as is recommended for bleeding patients (power 55 W, divergence angle 4 degrees, with CO2 gas-jet assistance). The experiments were performed during sterile laparotomy in heparinized dogs. Bleeding gastric ulcers were photocoagulated until bleeding stopped and then examined histologically 7 days later when depth of tissue injury was maximal. In the first series of experiments, the Nd:YAG laser was compared with the 7-W argon laser in the same dogs. Both lasers stopped bleeding from all experimental ulcers. The 55-W Nd:YAG laser caused full-thickness injury to the gastric wall beneath 11 of the 14 treated ulcers, whereas the 7-W argon laser caused no full-thickness injury beneath 14 treated ulcers. In a second series of experiments, we tried to determine whether varying exposure times with the 55-W Nd:YAG laser would make it less injurious; it did not. In a third series of experiments, the 55-W Nd:YAG laser was tested with and without CO2 gas-jet assistance in order to determine if this would affect the depth of injury; it did not. In the final series of experiments, the wattage of the Nd:YAG laser was varied to see if this would reduce depth of injury; lower wattage did not stop bleeding, and intermediate and higher wattages did stop bleeding but did not reduce depth of injury. We conclude that the 55-W Nd:YAG laser as it is currently used clinically produces deeper tissue damage than the argon laser in our animal model. This damage is not reduced by changes in power, duration of exposure, or the presence of gas-jet assistance.

Animals↗

Failure of cyanoacrylate tissue glue (Flucrylate, MBR4197) to stop bleeding from experimental canine gastric ulcers.

A plastic tissue adhesive, trifluoroisopropyl 2-cyanoacrylate (Flucrylate (TM), MBR4197), was tested for hemostatic efficacy in acute laparotomy experiments using a canine model of acute bleeding gastric ulcer. An improved delivery system suitable for endoscopic use was developed. Hemostatic efficacy of the adhesive was tested in both briskly bleeding ulcers and in oozing ulcers after partial treatment with a heater probe. In pilot studies at laparotomy, primary and adjunctive cyanoacrylate therapy of 81 bleeding ulcers were evaluated in seven unheparinized foxhounds. Hemostasis was produced in 11% of ulcers treated with cyanoacrylate alone and in 31% of ulcers treated with cyanoacylate as an adjunctive after partial heater-probe treatment; no sham-treated control ulcers stopped bleeding under the conditions of the experiment. To evaluate Flucrylate (TM) using out standard heparinized ulcer model, a randomized study was performed in six heparinized foxhounds at laparotomy. Ulcers were randomized to treatment with cyanoacrylate alone, adjuctive cyanoacrylate, heater probe alone or untreated control. Sham-treated control ulcers or ulcers treated with cyanoacrylate alone did not stop bleeding; 42% of ulcers treated with cyanoacrylate as an adjunctive stopped bleeding; all ulcers treated with a heater probe stopped bleeding. In this experimental model of acute bleeding gastric ulcer, trifluoroisopropyl 2-cyanoacrylate (Flucrylate(TM),MBR4197) did not stop severe bleeding and was unpredictable as an adjunctive treatment.

Animals↗