834 Letters.Book reviews graphic brush cytology hasproved negative by
using a fine spring-loaded Tru-cut needle Biopty gun(Biopty TM,Radiplast,Uppsala), percutaneously under ultrasound guidance.
Theuse of selfexpanding metalstents was alluded to intheleadingarticle, andaprimary indication wouldbe thosepatients with non-resectable hilar cholangiocarcinoma in whom goodsurvivalmightbeexpected. There isno evidence that theoptimum routeof insertion for these metalstents is via thetranshepatic route, and there are many advantages in placing metal stentsendoscopically.
Low strictures
Messrs Russell and Rees failedto reference Roux en Y choledochojejunostomy as the preferred procedure forbiliary drainage, for thereis noneexceptsurgicalhistory. Infact, conventional choledochoduodenostomy is an adequatebypass and this has the added advan-tage ofeasingendoscopic procedureslater if nodes or tumour growth around the porta hepatis occlude the bile duct.
We agree that there are a few figures suggesting animproved survival after radical resection, but numbersaresmall and veryfew centresachievea5%mortality,andcures are rare. The improved survival maymerely in-dicate theimproved selection.
Weagree with Professor Cotton that diffi-culties do arise in the management ofa few patients for whom resective surgery may be the correctapproach. The patientsarebestcared for in aunit which has a specialist team of interventionalendoscopists, radiologists, and a pancreatobility surgeon.
In the article routine stenting was not advocated; infact, itwas clearly pointedout that clinicians now have to take a mature approach intheir decision making, and have to balancethe patient's condition andlikelihood of survival beforedecidingon asurgicalor an endoscopic approach to palliation. Clearly, therearegoingtobesomepatients who lookfit andwell, and in whom some form of surgical palliation may be appropriate to reduce the needfor admissions, whichwouldbenecessary inthe patient stented endoscopically. At the other end of the spectrum there are those patients over the age of70years inwhom a simple stenting procedure seems a very suitable alternative toanyform of surgicalpalliation, particularly,whenweknow thatmostpatients die jaundice free with their original stent in situ. A RWHATFIELD RCG RUSSELL Department ofGastroenterology, MiddlesexHospital, LondonWIN8AA 1 Polydorou AA, Cairns SR, Dowsett JF, et al. Palliationofproximalmalignant biliary obstruc-tion by endoscopic endoprosthesis insertion. Gut1991,32: 685-9.
2CottonPB.Endoscopic management of bile duct
stones:(apples and oranges). Gut 1984; 25:
587-97.
Ultrastructural demonstration of histamine in humanenterochromaffinlike
celi
granules SIR,-Weread withgreat interest the paper by Lonroth et al.' By usingimnmunohistochemical
methods in lightmicroscopy in normal volun-teers, the authors showed that in addition to mast cells some gastric endocrine cells con-tained histamine. These cells were located exclusively in the fundus, constituted 44% of the total number of endocrine cells in the oxynticmucosa, and stored neither 5
hydroxy-100nm _ .
Ultrastructural histamine demonstrationin enterochromaffin like cell secretorygranuleson humanfundusbiopsy section. The 5nmgold particles are located in the electron densegranules andinsideatypical vacuolatedgranule(original magnificationx60,1O0).
tryptaminenorsomatostatin. These endocrine cellsweresupposedtobeenterochromaffinlike cells.
To study thishypothesis,wetriedto demon-stratehistamine(HA) in the enterochromaffin like cells byanimmunocytochemical method in electron microscopy. Ultrastructural analysis of fundic sections, indeed, allow enterochromaffin like cellstobedistinguished, with theirtypical secretory granules,from the othergastricendocrinecells.2 Thisstudywas done in a patient with pernicious anaemia, hypergastrinaemia(>1000 pg/ml), and micro-nodularhyperplasia of argyrophilic cells (Gri-meliusargyrophil technique). Fundic mucosal biopsy specimenswereobtainedduring gastro-scopy, fixed in4%glutaraldehyde in phosphate buffer at 20°C, dehydrated in ethanol, and embedded in Epon 812. Ultrathin sections werecut and mounted on gold grids. They wereincubated forfour hours in 1/200 diluted polyclonal guinea pig anti-HA antibodies (Pen-insula ref 61069) at room temperature and rinsed in phosphate buffer and in distilled water.Thegridswerethenincubated for one hour in a 5 nm gold particle conjugated antiguinea pig immunoglobulin (Biocell EMGAG5), 1/20 diluted in phosphate buffer solution. Finally, the grids were rinsed in water, dried, and contrasted with uranyl ace-tatein ethanol.
The efficiency and the specificity of the immunocytochemical reaction were first checked on rat peritoneal mast cell (PMC) sections. Normal rat PMC granules were shown to contain HA while, after in vitro incubation in a poly-L-lysine (secretagogue) solution,3 the PMC granules no longer con-tained HA.
Inthe humanbiopsy sections few mast cells were present around the gland. They were shown to contain HA in their uniformly electron dense granules. Theenterochromaffin like cells were identified ultrastructurally. Most of these cells contained granules pos-itively marked by the anti-HA immunocyto-chemical reaction(Figure). This reaction was reproduced severaltimesonmanysections of the same biopsy specimen with concordant results. The control sections were incubated either with anti-HA neutralised by HA followedby the immunogold reaction, or with immunogold reagent alone. They were both negative exceptalightaspecific background. The results of this study are in agreement with Lonroth's conclusions: the histamine-containing endocrine cells of the human fundus are enterochromaffin like cells. The role of these cells in the physiology of histamine mediated acid secretion should be explored. Further studies should
determiine
if the cell granules release histamine under the influence ofgastrin.J DELWAIDE MVIVARIO
JBELAICHE ELOUIS
RCOURTOY PGAST
J BONIVER Department ofGastroenterology and Department ofPathologicAnatomy, University ofLtige, CHUSart Timan B-4000Liege, Belgium Correspondenceto:DrJeanDelwaide.
1 Lonroth H, Hakanson R, LundellL,SundlerF. Histamine containing endocrine cells in the humanstomach. Gut1990;31: 383-8. 2Hakanson R,BottcherG, SundlerF, VallgreenS.
Activation and hyperplasia of gastrin and enterochromaffin-like cells in the stomach. Digestion 1986; 35 (suppl 1): 23-41.
3 Courtoy R,BoniverJ, SimarLJ.Cytochemistryof mousemast cellreaction to polylysine. Histo-chemtistry1980;66:49-58.
Reply
SIR,-Dr Delwaide and colleagues havewith thisreport furtherconfirmed that the entero-chromaffin like cells of the human fundus indeed contain histamine.Inthe humangastric mucosa thesecells are confined to the oxyntic gland area, which also presents a higher histidine decarboxylaseactivity than the non-acidproducingpyloric glandregion.'Patients withhypergastrinaemia of different origin also have ahigherhistidinedecarboxylase activity together withan increaseddensity of entero-chromaffin like cells in the oxyntic gland area.2' In addition, pentagastrin infusion is followed by a release of histamine and by a substantial increase inhistidinedecarboxylase activity in the oxyntic glandmucosaofhealthy volunteers. These penragastrininduced events donot occurin thepyloricglandregion.4
In conclusion, all this circumstantial evidence together with the results presented by Dr Delwaide andcolleagues favour the view that the enterochromaffin like cells of the human stomach store histamine, release the amine on proper stimulation, and have the capacitytosynthesise histamine.
HLONROTH University ofGoteborg, DepartmentofSurgery II, S-413 45Goteborg,Sweden 1 LonrothH,Lundell L, Rosengren E. Histamine metabolism ofthe human stomach-a study on
the regional distribution of the amine and enzymeactivities.ScandJClin Lab Invest 1989;
49:23-31.
2 Cattan D, Roucayrol AM, Launay JM, CallebertJ, CharaszN, Nurit Y, et al. Circulatinggastrin, endocrinecells,histamine content and histidine decarboxylase activity in atrophic gastritis. Gastroenterology1989;907:586-96.
3 BordiC,CocconiG, Togni R, Vezzadini P, Missalo G.Gastric endocrinecell proliferation; associa-tion with Zollinger Ellison syndrome. Arch Pathol1974; 98:274-8.
4 LdnrothH, Lundell L, Rosengren E, Olbe L. Histamine metabolism of the human gastric
mucosa - effect of pentagastrin stimulation. Gastroenterology1990; 98: 921-8.
BOOK
REVIEWS
Textbook of secretory diarrhea. By Emanuel Lebenthal and Michael E Duffey. (Pp 456; illustrated; $132.) New York: Raven Press,
1990.
Although secretory diarrhoea is noteveryone's cup of tea, I approached this book with some
