Expression of the 3-fucosyl N-acetyllactosamine (CD 15) antigen in normal, metaplastic, dysplastic, and neoplastic squamous epithelia

The 3-fucosyl N-acetyllactosamine residue is the antigen recognized by the monoclonal antibody MC2. Using MC2, we demonstrated the distribution of this antigen in a variety of squamous epithelia. The antigen is expressed to a variable degree on supra-basal cells in most normal non-keratinizing squamous mucosae, with a similar distribution in metaplastic squamous epithelia; antibody-labelled latex microspheres and immunogold electron microscopy show the antigen to form part of the glycocalyx. In dysplastic and neoplastic squamous lesions, expression is reduced or absent except in cells around areas of differentiation. Prior neuraminidase treatment of sections had little effect on the amount or distribution of demonstrable antigen. Expression of this antigen by cells in non-keratinizing squamous epithelia gives an indication of cell maturity and may provide a histological marker for the grading of dysplastic and malignant squamous mucosal lesions. A possible role for these carbohydrate residues in squamous mucosal defence is discussed.

Limited value of type III intestinal metaplasia in predicting risk of gastric carcinoma

Endoscopic gastric biopsy specimens taken in 1976 from 174 patients were reviewed. Biopsy specimens from 44 patients showed intestinal metaplasia, and subtyping by mucin histochemistry showed that 16 were of type I, 14 of type II, and 14 of type III. Only two of these 174 patients developed gastric adenocarcinoma over the next 10 to 11 years: one with type II and one with type III intestinal metaplasia. Case notes of a separate group of 68 patients with gastric adenocarcinoma diagnosed in 1985 were reviewed for evidence of intestinal metaplasia in a previous gastric biopsy. Only two patients had previously been biopsied; one of these biopsy specimens showed type II intestinal metaplasia and the other showed no intestinal metaplasia. These findings suggest that subtyping of intestinal metaplasia in endoscopic gastric biopsy specimens is of only limited value in identifying patients at risk of gastric adenocarcinoma who require long term follow up.

Characteristics of cholesterol absorption by human gall bladder: relevance to cholesterolosis

The characteristics of cholesterol uptake by 83 human gall bladders (obtained at cholecystectomy) were studied with a modified Ussing technique. Real and artificial biles labelled with 14C-cholesterol and 3H-dextran (the latter to correct for adherent mucosal bile) were used; all gall bladders absorbed cholesterol (average 3.5 nmol/cm2/minute). Recovery of the absorbed cholesterol from the tissue showed that about 4% was esterified over 60 minutes. In artificial bile the rate of absorption of cholesterol increased as the bile saturation index rose, but became constant once supersaturation was achieved. In contrast, supersaturated real bile permitted greater absorption of cholesterol, possibly due to enhanced cholesterol solubilisation. Preincubation of gall bladder tissue in sodium cyanide (5 mM) caused a 30% reduction in cholesterol uptake indicating that, although absorption is predominantly a "passive" process, there is a partial "active" component. There were no pronounced differences in the rate of cholesterol absorption as gall bladders became more diseased, but there was a reduction in the amount of cholesterol ester formed.

Permeability of the mouse gallbladder to blood-borne horseradish peroxidase

Horseradish peroxidase (HRP) was administered intravenously to mice by bolus injection. The subsequent uptake and fate of the HRP by the lateral and basal cell surfaces of resting and stimulated gallbladder epithelial cells was followed by light and electron microscopy. At 10 min after injection, HRP was visible in the lamina propria of the gallbladder and within 20 min of injection, HRP had permeated the basement membrane and had entered the lateral intercellular space, extending as far as the apical tight junction. Over the following 30 min, there was evidence of vesicular epithelial HRP uptake and 1 h after injection, HRP was visible in epithelial secretory granules within the lumen of the gallbladder and apical transport vesicles. These data provide evidence of a blood-to-bile transport pathway which could represent an important route of entry to bile by various blood-borne macromolecules.

Collagenous colitis associated with small intestinal villous atrophy

Two patients diagnosed as having small intestinal hyperplastic villous atrophy and being treated with a gluten free diet were investigated because of persistent watery diarrhoea. Both were found to have collagenous colitis. Previous reports of this condition have emphasised the presence of normal small intestinal mucosal architecture and the association of collagenous colitis with intestinal villous atrophy has not previously been reported. Both cases responded to oral steroid therapy, but not to other previously recommended treatment regimens.

Macrophages and mast cells in chronic cholecystitis and "normal" gall bladders

An attempt was made to quantify mast cells using toluidine blue and macrophages, with alpha-1-antitrypsin as a marker, from adjacent sections in the mucosa of two groups of gall bladders showing either minimal inflammatory change or established chronic cholecystitis. The results were expressed as cells/mm2 of mucosa. Alpha-1-antitrypsin showed both macrophages and mast cells, and therefore an estimate of macrophage numbers was obtained by subtraction. Mast cells comprised more than 60% of the alpha-1-antitrypsin positive cells. There were significantly (p greater than 0.001) more mast cells and macrophages in minimal inflammatory gall bladder mucosa than in established chronic cholecystitis.

Previously unreported abnormalities of dermal basement membranes and collagen fibrils in a patient with X-linked spondyloepiphyseal dysplasia tarda

Electron microscopic findings of the skin biopsy of a boy with spondyloepiphyseal dysplasia tarda showed several novel features. The basement membrane of the epidermis showed focal irregular thickening and reduplication. The collagen fibres showed foci of fibrous long spacing collagen and marked variation in fibre diameter. Taken together these abnormalities have not been reported in any other condition.

Business management in agricultural practices

Veterinarians tend to look upon themselves as professionals first, and as businessmen either second or not at all. This was the main conclusion of a study of 10 livestock practices mainly in the Lakelands area. The study attempts to show that by ignoring standard marketing and accounting procedures, they are wasting an opportunity to improve their financial efficiency and the quality of service they provide. Both these qualities will become more and more important in an increasingly competitive world, it says.

Effects of colchicine on the gallbladder of the mouse

The effects of colchicine on the mouse gallbladder followed a course depending on the dosage given (0.4-4 mg/100 g body weight). Following 0.5 mg/100 g, by 16 h there was a marked cholestasis with dilatation of the gallbladder and steatosis. There were progressive alterations in the Golgi apparatus and accumulation of vesicles. The apical mucous droplets decreased in number and became pleomorphic and dispersed throughout the cytoplasm. Lipid droplets appeared in numbers on the epithelial cytoplasm. By 48 h the tissues had reverted to normal appearances. When cholecystokinin, pilocarpine or ceruletide were given to animals which had received colchicine 18 h previously, the excess bile from the dilated gallbladder was discharged into the duodenum, remaining apical mucous droplets secreted and electron dense material accumulated in the lateral intercellular space. This formed a quasi-regular array between the epithelial bases and the basement membrane. Biochemically there was a significant decrease in alkaline phosphatase activity and a significant increase in acid phosphatase activity.

Muscle fibre typing in the human pharyngeal constrictors and oesophagus: the effect of ageing

Myosin-ATPase fibre typing revealed type 1 predominance (81%) in the human oesophagus and type 2 predominance in the pharyngeal constrictor (33% type 1) indicative of widely different functions. Fibre diameters were around 30 microns, significantly smaller than skeletal muscle. No significant change in mean fibre diameter or percentage of fibre type was seen with ageing, but atrophy and compensatory hypertrophy led to an increased variability in fibre diameters with age. No sex differences were observed, probably reflecting a similar usage of these muscles and contrasting with skeletal muscle.

Liver biopsies from patients with psoriasis related to photochemotherapy (PUVA): findings before and after 1 year of therapy in twelve patients. A blind study and review of literature on hepatotoxicity of PUVA

In each of twelve patients with psoriasis, a liver biopsy was taken before and after 1 year of photochemotherapy (psoralen and long-wave ultraviolet light; PUVA). The mean dose of psoralen was 3,204 mg (range, 1360-5300) at the time of the latter liver biopsy, whereas the mean number of treatments was seventy-nine (range, 34-126 treatments). Analysis by the sign test showed no statistically significant differences in any of the light microscopic variables comparing pre- and posttherapy liver biopsies. No changes were found that appeared to be specific for PUVA therapy. Psoralen, in the doses given as part of PUVA therapy for 1 year in a limited number of patients, seems to have little hepatotoxicity. The literature on the possible hepatotoxicity after treatment with psoralen followed by ultraviolet A irradiation is reviewed. Patients receiving PUVA therapy should have only limited alcohol intake. From this reading, psoralens as part of PUVA therapy appear to have little or no hepatotoxicity.

The effects of mucus on the binding of cationized ferritin by human and animal gastrointestinal epithelium

Human gallbladder and gastric epithelial cells are normally covered with a layer of mucus. When specimens were exposed to cationized ferritin (CF) in vitro, they did not regularly bind nor internalise it. If the tissues were first exposed to the mucolytic agents cysteamine or pepsin, then the gallbladder epithelium readily bound CF and the gastric epithelium irregularly. The in vivo binding of CF by guinea pig gallbladder could be abolished by the induction of mucous hypersecretion by the antibiotic lincomycin. The removal of the mucus by mucolytic agents restored the binding of CF. The irregular binding of CF by gastric mucosa after the use of mucolytic agents suggests other factors may be at play.

Human oesophageal submucosal glands. Their detection mucin, enzyme and secretory protein content

Human oesophageal submucosal glands may be regularly demonstrated by first exposing the oesophageal lumen to toluidine blue which reveals the duct ostia. Four types of cell were identified in the glands - mucous, subsidiary or serous, myoepithelial and oncocytes. The mucous cell contained neutral, sialated and sulphated mucins. The subsidiary cells held smaller amounts of neutral and sialated mucin, plus fucosyl residues. No lipids were detectable histochemically. ATP-ase and alkaline phosphatase were shown in the capillary endothelium. The duct epithelium showed some nonspecific esterase activity not sensitive to E 600. By immunoperoxidase techniques, the duct epithelium was shown to be rich in cytokeratin. The subsidiary cells contained lysozyme, CEA and pepsinogen. B lymphocytes composed most of the periductular lymphoid aggregates, although some T cells were found there and also intraepithelial and subepithelial in relation to the stratified squamous epithelium lining the oesophagus. Langerhans' cells were also demonstrated as intraepithelial by several techniques.

The characterization and energetic potential of brown adipose tissue in man

In adult man, brown fat can be detected in perinephric fat depots by visual inspection, electron microscopy and nucleotide binding to the tissue-specific uncoupling protein. The 32 kDa uncoupling protein is functionally active, showing a nucleotide-sensitive conductance to protons and an uncoupling response to fatty acids. The amount of uncoupling protein in human mitochondria is equivalent to that in a partially cold-adapted guinea pig, indicating some potential for thermogenesis. Respiratory capacity measurements indicate that the total perinephric fat in adult man can only account for one-fivehundredth of the whole-body response to infused noradrenaline. Thus, although brown fat has been found to be quantitatively important in animal studies, considerable caution must be exercised in extrapolating its significance to adult man.

Lipid in the human gallbladder mucosa. A histochemical study by light and electron microscopy

The distribution of lipids in the epithelium of 70 gallbladders removed for cholecystitis was investigated histochemically. Lipid was demonstrated in 68 gallbladders--cholesterol and its esters, triglycerides, free fatty acids and phospholipids. Neutral lipid was found at the bases of epithelial cells in 90 per cent and at the apex in 10 per cent of the gallbladders. Phospholipid was shown at the apex of epithelial cells in 64 per cent of the gallbladders. Electron microscopy in 12 specimens revealed cholesterol in and between the epithelial cells and in the underlying connective tissue.

Proteinase-like peptidase activities in malignant and non-malignant gastric tissue

Activities of several proteinase-like peptidases have been determined in homogenates of malignant tissue, non-malignant tissue adjacent to the tumour (A-NM) and non-malignant tissue distant to the tumour (D-NM) from 17 patients undergoing surgery for histologically confirmed gastric malignancies. In homogenates of malignant tissues the activities of collagenase, cathepsin B, cathepsin (B+L), cathepsin H and cathepsin D were significantly higher than in D-NM tissues. By contrast, the levels of plasminogen activator were significantly lower in malignant tissues than in the D-NM tissues. Furthermore, the activities of collagenase-like and the cysteine-proteinase-like peptidases in the A-NM tissues were lower than in malignant tissues but higher than in the D-NM tissues. Separation of full-thickness non-malignant tissues into mucosal and seromuscular layers revealed significantly higher activities in the former. The elevated levels of these proteinase-like peptidases in homogenates of gastric cancer tissue suggests an important role for these enzymes in tumour invasion.

Cholesteryl esters in human gallbladder bile and mucosa

Cholesteryl esters, identified by thin-layer and gas-liquid chromatography followed by mass spectroscopy in a few cases, were found in all human bile samples analysed. The amount varied extensively both in absolute concentration and when expressed as a percentage of the total cholesterol present. In about 30% of samples, the percentage of ester exceeded 4% of total cholesterol but there was no clear association with the presence of cholesterol gallstones or pigment stones, nor was there any association with the lithogenicity of bile.

Microwave fixation: its potential for routine techniques, histochemistry, immunocytochemistry and electron microscopy

Human tissues, both biopsy and postmortem, and tissues from rodents were fixed by microwaves at various temperatures and compared against formaldehyde-fixed material. Conventional stains, including trichromes, worked well. Red cells were lysed, but white cells were fixed, thus permitting diagnoses of various inflammatory states. Malignant cells were equally well-preserved by the two methods. Histochemical investigations of mucosubstances, lipids and various hydrolases showed no significant difference between the two techniques. Some neurological stains, however, were not as good following microwave treatment. Immunocytochemical localization of IgA, IgM and IgG showed no significant difference after microwave fixation compared to that in tissues fixed with formaldehyde. Microwave fixation did not lead to a greater tissue shrinkage than that obtained with formaldehyde fixation. Both were significantly less than that following treatment with phosphate-buffered saline alone. Electron microscopy gave results which were interpretable, but with damage resembling early postmortem change. Microwave fixation is complete in approximately 1-2 min. The mechanism of fixation appears to be due to denaturation associated with disulphide bond formation and a decrease in solubility of proteins.

The uptake of cationized ferritin by guinea-pig gall bladder in vitro

Tissue pieces of guinea-pig gall bladder were grown in vitro for up to ten days. Over this period at different intervals, specimens were exposed to cationized ferritin in culture medium for 1 h and then grown in ferritin free medium for up to 24 h. Other specimens were grown in culture medium containing cationized ferritin for up to 24 h. Both treatments produced a similar morphological sequence. Electron microscopy at all intervals studied showed the cationized ferritin was first bound by the apical cell membrane, clumped and internalized in large 400 nm vesicles. It was then carried to lysosomes in the region of the Golgi apparatus. Within 1 h, the marker was exocytosed in clumps into the lateral intercellular space, accumulating against the basement membrane in a roughly regular approximately 60 nm array. This pathway of cationized ferritin through the gall bladder epithelium is the same as that followed in vivo although the time taken was shorter in vitro.

Human gallbladder epithelium: non-specific esterases in cholecystitis

Esterases active at neutral and acid pH have been demonstrated in human gallbladder epithelium. Reaction to a wide variety of inhibitors and activators suggests that they probably represent the same enzyme with two active sites while a close correlation with acid phosphatase, a known lysosomal enzyme, suggests a lysosomal localization. Esterase activity in the gallbladder mucosa in significantly decreased in chronic cholecystitis. Polyacrylamide gel electrophoresis suggests that cholesterol stones may be associated with a specific type of isoenzyme pattern. Esterase positive cells are present in the inflammatory infiltrate in the lamina propria of the gallbladder in most cases of chronic cholecystitis. Naphthol AS-D chloracetate esterase staining indicates that mast cells form a large part of the infiltrate. Bile acids modulate the enzyme activity in vitro. Although the exact substrate specificity is not known, several possibilities are discussed, implicating esterases in the pathogenesis of chronic cholecystitis.

The uptake of lead by small intestine, colon and gallbladder of the guinea pig in vivo

The binding and uptake of lead by the jejunal, colonic and gallbladder epithelium of guinea pig has been investigated by electron microscopy. Binding occurred rapidly, the most marked by the microvilli was by the jejunum, followed by colon and gallbladder. The tracer was subsequently internalised in small membrane bound vesicles and smooth endoplasmic reticulum. By 30 min, it appeared in multivesicular bodies at all three sites.