Cytokeratin expression in oral exfoliative cytology: effect of temperature and fixation

The identification of keratin expression within oral cytology may be useful in the diagnosis of clinically suspicious oral mucosal lesions. There may be wide variation in the temperature at which such smears are stored, prior to processing. Conventionally, rapid fixation or storage at low temperatures is recommended to preserve kertin expression within tissue biopsies. No previous study has assessed whether this is true for oral cytology. Smears were taken from clinically normal buccal mucosa. For each temperature assessed (-70, -40, -22, +5, +20 and +26 degrees C), one smear was spray-fixed (Vale Smear Fix) and one air-dried, prior to storage for 4 days, and then staining with the pan-epithelial antikeratin antibody, LP34. Preservation of keratin expression was assessed as either weak (zero to few positive cells) or strong (most cells positive). The results were analysed using logistic regression with the statistical modelling package, GLIM. Over the range of temperatures studied, spray fixation did not appear to improve the identification of keratin expression. Although the best preservation was obtained at lower temperatures, keratin expression was still adequate after 4 days at 20 degrees C. Hence, a delay in processing of 4 days would still allow detectable expression in oral exfoliative cytology even at room temperature.

Glycogen storage disease diagnosed in adults

Glycogen storage diseases are usually identified in childhood. We present the clinical, biochemical and histological features of 10 patients first diagnosed in adult life. Five had glycogen storage disease type 1a, one type 1c, two type IX, and in two patients there were previously unreported abnormalities of hepatic glucose-6-phosphatase system activity. Of the latter, one patient had an inhibitor of liver glucose-6-phosphatase (pseudo-1b glycogen storage disease) the other having abnormal glucose-6-phosphatase activity and microsomal pyrophosphate transport. A glucagon test is suggested as a useful screening procedure. Glycogen storage disease should be considered in adults with symptoms suggesting hypoglycaemia.

Flow-cytometric analysis of growth-regulatory peptides and their receptors in Barrett's oesophagus and oesophageal adenocarcinoma

The conventional assessment of the premalignant potential of Barrett's oesophagus is unsatisfactory. However, it has recently been shown that abnormalities of growth-regulatory peptides and their receptors may be important in the pathogenesis of this condition. In an attempt to improve the diagnostic and prognostic criteria we have studied 21 consecutive patients with Barrett's oesophagus and 7 others with adenocarcinoma of the oesophagus. In each patient biopsy specimens were taken from the columnarlined oesophagus or the adenocarcinoma and from the gastric cardiac mucosa for routine histologic evaluation. Immediately adjacent specimens were taken from both the Barrett's mucosa or adenocarcinoma and from the gastric mucosa for flow-cytometric study. The latter samples were disaggregated and labelled with antibodies to epidermal growth factor (EGF), transforming growth factor alpha (TGF-alpha), and epidermal growth factor receptor (EGF-R). The flow cytometer selected cells labelled with each antibody and expressed them as a percentage of the total number of disaggregated cells (average, 5500 cells). Epidermal growth factor receptors were expressed in a greater number of cells from Barrett's mucosa, with the intestinal type or those with dysplasia, than in gastric cardiac mucosa (p less than 0.05). All seven adenocarcinoma had many more cells expressing EGF, TGF-alpha, and EGF-R than normal gastric mucosa (p less than 0.01). We conclude that flow-cytometric evaluation of EGF-R can help in the understanding of the pathogenesis of Barrett's oesophagus.

Abnormal expression of growth regulatory factors in Barrett's oesophagus

1. In order to assess potential abnormalities in the control of mucosal proliferation, 30 patients with Barrett's oesophagus were studied in order to evaluate the presence and distribution of epidermal growth factor, transforming growth factor-alpha and epidermal growth factor receptor to determine the Ki-67 labelling index in the affected oesophageal mucosa. Serial sections were analysed immunohistochemically. Ten of the patients had adenocarcinoma in the Barrett's mucosa and the other 20 had differing histological types of Barrett's mucosa (10, intestinal-type; 10, fundic- or cardiac-type). 2. The expression of transforming growth factor-alpha, epidermal growth factor and epidermal growth factor receptor was increased and the Ki-67 labelling index was higher in Barrett's mucosa compared with normal gastric mucosa. The 'intestinal-type' of Barrett's mucosa had the greatest expression of transforming growth factor-alpha, epidermal growth factor receptor and the highest Ki-67 labelling index compared with the other types of Barrett's metaplasia. Five cases of 'intestinal-type' Barrett's metaplasia had especially high Ki-67 labelling indices and these patients over-expressed both transforming growth factor-alpha and epidermal growth factor receptor. The patients with adenocarcinomas in the Barrett's mucosa also over-expressed transforming growth factor-alpha and epidermal growth factor receptor, but not epidermal growth factor, compared with normal gastric mucosa. 3. In conclusion, both normal gastric mucosa and Barrett's mucosa have potential autocrine growth regulatory mechanisms, but Barrett's mucosa has increased expression of both of the measured ligands and of the epidermal growth factor receptor.

Mucosal function after ileal mucosal fenestration and colonic autotransplantation

A method of small bowel mucosal augmentation called ileal mucosal fenestration and colonic autotransplantation (IMFCA) was devised and tested in pigs. In this technique, a vascularized mucosal graft was harvested from a 12-cm ileal loop, fenestrated by serial incision and then expanded to 20 cm. A 20-cm colonic loop was isolated and surgical mucosectomy was carried out. The fenestrated ileal mucosal graft was then autotransplanted into the prepared colon and the resulting composite structure was exteriorized as a Thiry-Vella loop. With this technique, ileal mucosal fenestrations healed by lateral epithelial in-growth, giving a new mucosal continuum within the recipient colon. At 60 days after surgery, the surface area of transplanted mucosa exceeded that within the original ileal loop by approximately 85 per cent. At this time, the transplanted mucosa had morphology and capacity for Na(+)-dependent glucose transport which were indistinguishable from those of control ileal mucosa.

Leakiness of gastric superficial and foveolar cells. A quantitative electron microscopic study using tannic acid

Two adjacent antral biopsies were taken endoscopically from 41 patients attending a clinic for the investigation of upper gastrointestinal tract symptoms. One was processed for histopathological grading and assessment of the Helicobacter pylori by light microscopy. The other was fixed in tannic acid, which demonstrates cell leakiness, and processed for electron microscopy. On each grid, the light (electron lucent) and dark (electron dense-leaky) gastric superficial and foveolar cells away from mechanical trauma of biopsy were counted, along with the number of H. pylori which were in contact with the epithelial cells. There was a significant relationship between histological grade of gastritis and the extent of electron microscopic damage, i.e., the degradation of normal to leaky cells and the number of H. pylori per leaky cell. If the patients were divided into two groups with minimal and maximal gastritis and compared against each other, then there was a significant difference between the two groups with respect to surface cell damage, polymorphs per unit area, the number of glands invaded by polymorphs, light/dark cells, Helicobacter grades assessed light microscopically or totals counted in contact with epithelial cells by electron microscopy, the number of Helicobacter per cell, and the age of the patients. There was no difference between the two groups on their endoscopic appearances or treatment with H2 blockers or NSAIDS.

Uptake of horseradish peroxidase by human oesophageal explants over 24 h

Human oesophageal biopsies, endoscopically and histologically normal, were incubated in Ham's F10 for periods up to 24 hours in the presence of horseradish peroxidase. The fluid phase marker was taken up most avidly by the prickle cells but to a lesser extent in the functional layers and by basal cells. Endocytosed markers proceeded to multivesicular bodies (segrosomes). Horseradish peroxidase was later deposited in lysosome-like structures and also in the Golgi apparatus. The lesser uptake by the functional cells may represent reduced access of the marker to the cells due to the intercellular barrier.

Semi-permeable microcapsules for cell culture: ultra-structural characterization

Microcapsules made from alginate-poly(L-lysine)-alginate membranes have been studied as vehicles for cell culture in a number of laboratories. We have examined their permeability, robustness and ultrastructure in detail. Permeability to globular proteins could be controlled by using poly-lysine of different mean MW in their construction. However, this parameter also affected the degree to which microencapsulated living cells leaked out of the capsules during and after preparation. Poly-lysine of low MW produced a relatively permeable and robust membrane whereas a high MW produced capsules with the reverse characteristics. A MW of 22,000 appears to be optimal in forming robust capsules which are relatively impermeable to high MW species such as immunoglobulins. The structure of the semipermeable membrane was investigated by electron microscopy and found to be complex but entirely consistent with the data on protein permeability and cell leakage. Microcapsules were not disrupted by gentle treatment with trypsin or chelating agents but dissolved with the addition of heparin, sodium dodecyl sulphate or sodium hydroxide. Empty microcapsules implanted into the peritoneal cavity of rats elicited a host cellular reaction but remained intact for at least three months.

Microencapsulation of human cells: its effects on growth of normal and tumour cells in vitro

The growth kinetics of established human colorectal tumour cell lines (HT29, HT115 and COLO 320DM) and human diploid fibroblasts (Flow 2002) were studied in conventional culture and in microcapsules formed from alginate-poly(L-lysine)-alginate membranes. The tumour lines grew rapidly in microcapsules but, in the case of the substrate-adherent lines HT29 and HT115, only after a prolonged lag phase. This phase was reduced by serial passage in microcapsules. The anchorage-independent line COLO 320DM showed no lengthening in lag phase. Microencapsulated fibroblasts underwent negligible growth but remained viable. Some evidence for functional differentiation (microvilli, cell-cell junctions) of the tumour line HT115 within the microcapsules was observed. We conclude that the use of microcapsules provides an alternative system with some advantages for the study of human cancer and its metastases in vitro.

Evidence for hypomotility in non-ulcer dyspepsia: a prospective multifactorial study

A prospective multifactorial study of symptoms and disturbance of gastrointestinal function has been undertaken in 50 patients with non-ulcer dyspepsia. Objective tests including solid meal gastric emptying studies, gastric acid secretion, E-HIDA scintiscan for enterogastric bile reflux, and hydrogen breath studies were carried out in all patients and validated against control data. Gastroscopy and biopsy were carried out in non-ulcer dyspepsia patients only. Non-ulcer dyspepsia patients were categorised on the basis of predominant symptoms as: dysmotility-like dyspepsia (n = 22); essential dyspepsia (n = 14), gastro-oesophageal reflux-like dyspepsia (n = 11); and ulcer-like dyspepsia (n = 3). In the total non-ulcer dyspepsia population, solid meal gastric emptying was delayed (T50 mean (SEM) = 102 (6) minutes (patients) v 64 (6) minutes (controls), (p less than 0.01) and high incidences of gastritis (n = 26) and Helicobacter pyloridis infection (n = 18) were found. An inverse correlation was observed between solid meal gastric emptying and fasting peak acid output (r = -0.4; p less than 0.01). Indeed gastric emptying was particularly prolonged in eight patients (T50 mean (SEM) = 139 (15) minutes) with hypochlorhydria. In the non-ulcer dyspepsia population oral to caecal transit time of a solid meal was delayed (mean SEM = 302 (14) minutes (patients) v 244 (12) minutes (controls) (p less than 0.01]. Seven patients had a dual peak of breath hydrogen suggestive of small bowel bacterial overgrowth. No association was observed between symptoms and any of the objective abnormalities. This multifactorial study has shown that hypomotility, including gastroparesis and delayed small bowel transit, is common in non-ulcer dyspepsia and may be related to other disorders of gastrointestinal function. No relation between symptoms and disorders of function, however, has been shown.

A comparison of microwaves and heat alone in the preparation of tissue for electron microscopy

Microwaves have been used to stabilize tissues from the gastrointestinal tract for scanning electron microscopy. The temperature reached is important. Above 55-60 degrees C, epithelial cell sheets begin to lift revealing the underlying basement membrane. These cells may be recovered from the supernatant by micropore filtration or the celloidin sock technique. At higher temperatures, produced either by microwave irradiation or in a water bath, more enterocytes are released. The epithelial cells are larger with increasing temperatures, less with microwaves than with heat alone or in the presence of formaldehyde. At 70 degrees C and above, some proteins are lost and there is false localization of RNA. Some immunoperoxidase reactions are still positive after exposure of the tissue to 60 degrees C. Tissues fixed in boiling formaldehyde retain a surprisingly good morphology.

Hepatic iron in dialysed patients given intravenous iron dextran

Five percutaneous biopsy and 17 necropsy liver specimens were analysed histologically and chemically for iron content in 22 patients receiving dialysis for chronic renal failure, 13 of whom were given intravenous iron-dextran. Brissot scores for assessing histological hepatic iron deposition and chemically measured liver iron concentrations correlated closely. Both variables depended on total cumulative dose of iron, and to a lesser extent, on time since the last dose. Fibrosis (seen in five patients) was minimal and non-specific. Electron microscopic examination showed that there was no generalised damage and confirmed the presence of iron in the hepatocytes in the form of ferritin. High liver iron concentrations, in excess of 1000 micrograms/100 mg dry weight, were seen in two patients. Four others given comparable cumulated amounts (18-23 g iron) did not have such high concentrations. Plasma ferritin concentrations were high in eight patients, some with and some without fibrosis. The risk of temporarily high iron deposition in the liver causing damage seemed to be minimal when weighed against the benefit of increased haemoglobin in most of the patients. Intravenous iron treatment merits further evaluation, particularly with the advent of erythropoietin treatment, which requires continuously available iron.

The effect of secretin on sodium ion absorption by the isolated human gallbladder

Sodium ion (Na+) transport, a principal function of the gallbladder epithelium, was studied by measuring the flux of 22Na across isolated human gallbladder mucosa maintained in a modified 'Ussing' flux chamber. Tissue was obtained from cholecystectomy specimens in symptomatic patients with cholelithiasis. Out of 26 gallbladders studied, 13 had a net Na+ flux from mucosa to serosa which indicated active Na+ absorption. The hormone secretin, when added to the serosal fluid, reversed the direction of net flux in these gallbladders and caused a secretion of Na+ from serosa to mucosa. These results suggest that secretin may be involved in the physiological regulation of fluid transport in the human gallbladder, and also suggest a possible role for this hormone in gallbladder emptying.

The microsomal glucose-6-phosphatase enzyme of human gall-bladder

Microsomes isolated from adult human gall-bladders have for the first time been shown to contain specific glucose-6-phosphatase activity. The gall-bladder glucose-6-phosphatase enzyme has the same molecular weight (36,500 daltons) and similar immunological properties and kinetic characteristics to the hepatic microsomal glucose-6-phosphatase enzyme.

Tissue fixation with phenol-formaldehyde for routine histopathology

The addition of 2% phenol had a marked accelerating effect on neutral buffered 4% formaldehyde as a fixative. Histopathological material fixed in buffered phenol-formaldehyde (pH 7.0) and rapidly advanced to paraffin in an enclosed tissue-processor showed improved nuclear and cytoplasmic detail, reduced shrinkage and distortion, and an absence of formalin pigment. Good results were obtained in less time when sequential fixation in phenol-formaldehyde buffered to pH 7.0 and pH 5.5 was carried out at an elevated temperature (40 degrees C) in the enclosed tissue-processor. Standard histological stains and immunoperoxidase methods worked well. In resin-embedded tissue, buffered phenol-formaldehyde (pH 7.0) gave satisfactory ultrastructural results. The penetration rate of buffered phenol-formaldehyde (pH 7.0) in gelatin models did not differ from that of neutral buffered 4% formaldehyde. Polyacrylamide gel electrophoresis showed enhanced protein polymer formation with buffered phenol-formaldehyde (pH 7.0) as compared with neutral buffered 4% formaldehyde. Protein polymer formation increased in response to increased time and temperature. Cells fixed in suspension in buffered phenol-formaldehyde (pH 7.0) and neutral buffered 4% formaldehyde showed similar volume changes.

Endocytotic pathways across the human gall-bladder mucosa: permeability studies using horseradish peroxidase

Human gall-bladder epithelium obtained straight from the operating theatre was incubated in an Ussing chamber with the fluid phase marker, horseradish peroxidase (HRP), for up to 60 min. When the marker was presented on the apical surface, within 30 min it had moved readily across the apical cytoplasm in transport vesicles to receptosomes and into the lateral intercellular space, extending across the basement membrane into the lamina propria. When HRP was presented at the basal aspect, within 30 min it had moved through the lamina propria, across the basement membrane and into the lateral intercellular space. By 60 min, only small amounts had been taken up by the epithelial cells and transported to receptosomes. These data indicate a rapid transmucosal endocytotic pathway for blood- or bile-borne macromolecules.

Buffered phenol formaldehyde (pH 7.0 and pH 5.5): improved fixation in an enclosed tissue processor

The addition of 2% phenol has a marked adjuvant effect on 4% formaldehyde as a fixative. Sequential use of phenol formaldehyde buffered to pH 7.0 and pH 5.5 results in improved fixation in material rapidly advanced to paraffin in an enclosed tissue processor. Sections stained with alum haematoxylin and eosin show improved nuclear and cytoplasmic detail, reduced tissue shrinkage and an absence of formalin pigment. Excellent results are obtained with conventional special stains and immunoperoxidase methods.

Studies on the mechanism of non-visualization of diseased human gallbladders during oral cholecystography

Oral cholecystography is a well established method for studying the human gallbladder and radiological non-visualization of the gallbladder has been shown to correlate highly with the presence of disease. The exact mechanism by which diseased gallbladders fail to visualize is unclear, but may be due to a failure of the gallbladder to concentrate the luminal contents. Concentration of gallbladder contents is achieved by the reabsorption of water, the driving force for which is active sodium (Na+) absorption. Therefore Na+ transport was studied by measuring the flux of Na22 across isolated human gallbladder mucosa (obtained at cholecystectomy) and compared with the results of oral cholecystography and histological grading. In 27 gallbladders studied, 59% absorbed Na+, whilst the remainder secreted Na+. Comparison with histological grading showed that as gallbladders became more diseased they absorbed less Na+ and were more likely to secrete Na+. In addition, gallbladders that absorbed Na+ were significantly more likely to visualize on cholecystography than those that secreted Na+. These results indicate that some diseased human gallbladders secrete, rather than absorb, Na+ and suggest that the mechanism for radiological non-visualization is failure of fluid absorption and the development of active fluid secretion.

Glycosaminoglycans in human gallbladder basement membrane: nature and quantitative changes in chronic cholecystitis

Using cuprolinic blue as a stain along with enzymic digestion, heparan sulphate has been identified as the main glycosaminoglycan in the basement membrane of human gallbladder epithelium. The amount of glycosaminoglycans was quantified by counting the number of molecular profiles cm-2 in electron micrographs of mildly, moderately and severely inflamed gallbladders. There is a significant increase (P = 0.009) in the amount of glycosaminoglycans in the basement membranes of severely inflamed gallbladders compared with cases of mild chronic cholecystitis. Differences, although present, are less significant when mild and moderate or moderate and severe cholecystitis are compared. The findings suggest that there is a continuous accumulation of heparan sulphate in the basement membrane in chronic cholecystitis which increases in amount with the severity of inflammation.

Sodium transport in the diseased human gallbladder and the effects of indomethacin

1. Sodium ion (Na+) transport, a principal function of the gallbladder epithelium, was studied by measuring the flux of 22Na across isolated, inflamed human gallbladder mucosa maintained in a modified 'Ussing' flux chamber. Tissue was obtained from cholecystectomy specimens in symptomatic patients with cholelithiasis. 2. In 30 gallbladders studied, 57% had a net Na+ flux from mucosa to serosa (Na+ absorption), while 23% had a net Na+ flux from serosa to mucosa (Na+ secretion). The remaining 20% showed no overall net Na+ flux. 3. Indomethacin added to the serosal fluid reversed the direction of net Na+ flux in secreting gallbladders and caused an absorption of Na+. In Na+-absorbing gallbladders, indomethacin caused a slight reduction in Na+ absorption. No change in Na+ flux was induced in gallbladders with no initial net Na+ flux. 4. These results demonstrate that instead of absorbing Na+, some inflamed human gallbladders may secrete Na+. As this secretion can be reversed to the more usual absorption by indomethacin, it is likely that this secretion is mediated by prostaglandins.

Expression of the CD 15 antigen is a marker of cellular differentiation in cervical intra-epithelial neoplasia (CIN)

The CD 15 antigen (3-fucosyl N-acetyllactosamine), present on the outer cell membrane of cervical squamous epithelial cells, is recognized by the monoclonal antibody MC2, which is similar to several commercially available antibodies. Staining sections of cervical biopsies with MC2 clearly demonstrates the zone of supra-basal differentiated cells in the normal squamous epithelium. Staining with MC2 also demonstrates the diminished proportion of this zone occurring with grades of CIN, reflecting progressive de-differentiation of the epithelium. In immature squamous metaplastic epithelium, absence of cytoplasmic differentiation is reflected by lack of staining. As expression of the CD 15 antigen by cervical squamous cells mirrors cytoplasmic maturity and is a marker of cellular differentiation, staining colposcopic biopsies with MC2 may aid the routine histopathological grading of CIN. A comparison is made between the staining pattern observed using MC2 with that of two commercially available antibodies (Leu M1 and Dako M1), and a possible role for the CD 15 antigen in cellular adhesion in squamous mucosae is discussed.

Differentiating the effects of microwave and heat on tissue proteins and their crosslinking by formaldehyde

Alkaline phosphatase activity in mouse liver blocks, cooled by an ice-bath, decreased by 50% in 5 min of microwave irradiation (280 W). This loss of protein tertiary structure has been mirrored by ultrastructural changes in the same tissue. Microwave irradiation did not produce cleavage or polymerization of lysozyme or haemoglobin. Protein formaldehyde reaction mixtures produced protein polymers between 0 degree and 40 degrees C which could be separated by SDS-polyacrylamide gel electrophoresis. Microwave irradiation of lysozyme or haemoglobin plus formaldehyde on ice-bath up to 30 min produced a similar electrophoretic pattern. When lysozyme or haemoglobin plus formaldehyde was heated to 60 degrees C for 30 min, the protein polymers migrated faster on electrophoresis, suggesting a smaller hydrodynamic volume than expected due to intramolecular crosslink formation, not opened up under the conditions of electrophoresis.

The fine structure and histochemistry of human bile duct in obstruction and choledocholithiasis

Biopsies from the common bile ducts from seven patients undergoing surgery for biliary obstruction due to stones or malignancy were studied histochemically and electron microscopically. The surface of the bile duct is lined by a tall epithelium which extends into diverticula. Apically, they contain some neutral and sialated mucosubstances. Fucosyl residues were found in the Golgi apparatus and along the apical cell membrane. The latter is lined by microvilli. There was a well-developed rough endoplasmic reticulum and Golgi apparatus and a small number of apical secretory droplets. Large numbers of lipid droplets were present basally in some cells. Lipid-containing macrophages were also seen intra-epithelially and in the lamina propria. This suggests a possible pathway for lipid transport. The glands were lined by cuboidal cells, some containing much mucus--sulphated, sialated, and neutral with a basal nucleus. A well-developed endoplasmic reticulum and Golgi apparatus were found with abundant secretory droplets. The glandular epithelium contained lysozyme, alpha-1-antitrypsin, and alpha-1-antichymotrypsin. These may play a protective role. The lamina propria contained scattered smooth muscle cells amongst the fibroblasts and inflammatory cells.