RESUMEN
PACAP is a neuropeptide with diverse functions in various organs, including reproductive system. It is present in the testis in high concentrations, and in addition to the stage-specific expression within the seminiferous tubules, PACAP affects spermatogenesis and the functions of Leydig and Sertoli cells. Mice lacking endogenous PACAP show reduced fertility, but the possibility of abnormalities in spermatogenic signaling has not yet been investigated. Therefore, we performed a detailed morphological analysis of spermatozoa, sperm motility and investigated signaling pathways that play a role during spermatogenesis in knockout mice. No significant alterations were found in testicular morphology or motility of sperm in homozygous and heterozygous PACAP-deficient mice in spite of the moderately increased number of severely damaged sperms. However, we found robust changes in mRNA and/or protein expression of several factors that play an important role in spermatogenesis. Protein kinase A expression was markedly reduced, while downstream phospho-ERK and p38 were elevated in knockout animals. Expression of major transcription factors, such as Sox9 and phospho-Sox9, was decreased, while that of Sox10, as a redundant factor, was increased in PACAP-deficient mice. The reduced phospho-Sox9 expression was partly due to increased expression and activity of phosphatase PP2A in knockout mice. Targets of Sox transcription factors, such as collagen type IV, were reduced in knockout mice. In summary, our results show that lack of PACAP leads to disturbed signaling in spermatogenesis, which could be a factor responsible for reduced fertility in PACAP knockout mice, and further support the role of PACAP in reproduction.
Asunto(s)
Biomarcadores/metabolismo , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa/fisiología , Túbulos Seminíferos/patología , Motilidad Espermática/fisiología , Espermatogénesis , Espermatozoides/patología , Animales , Masculino , Ratones , Ratones Noqueados , Proteína Fosfatasa 2/metabolismo , Reproducción , Túbulos Seminíferos/metabolismo , Espermatozoides/metabolismoRESUMEN
Dysregulation of neuropeptides may play an important role in aging-induced impairments. In the long list of neuropeptides, pituitary adenylate cyclase-activating polypeptide (PACAP) represents a highly effective cytoprotective peptide that provides an endogenous control against a variety of tissue-damaging stimuli. PACAP has neuro- and general cytoprotective effects due to anti-apoptotic, anti-inflammatory, and antioxidant actions. As PACAP is also a part of the endogenous protective machinery, it can be hypothesized that the decreased protective effects in lack of endogenous PACAP would accelerate age-related degeneration and PACAP knockout mice would display age-related degenerative signs earlier. Recent results support this hypothesis showing that PACAP deficiency mimics aspects of age-related pathophysiological changes including increased neuronal vulnerability and systemic degeneration accompanied by increased apoptosis, oxidative stress, and inflammation. Decrease in PACAP expression has been shown in different species from invertebrates to humans. PACAP-deficient mice display numerous pathological alterations mimicking early aging, such as retinal changes, corneal keratinization and blurring, and systemic amyloidosis. In the present review, we summarize these findings and propose that PACAP deficiency could be a good model of premature aging.
Asunto(s)
Envejecimiento/fisiología , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa/deficiencia , Animales , Ratones , Modelos AnimalesRESUMEN
Monoclonal antibodies which recognize different epitopes on either titin or nebulin show normal staining patterns on frozen sections of three muscle biopsies of Duchenne muscular dystrophy (DMD). Gel electrophoresis and immunoblotting performed on two of these muscle biopsies show the normal pattern of titin and nebulin polypeptides. Since the donor of one of these biopsies has a large deletion of the 5'-region of the DMD gene, our results argue against the recent proposal that nebulin is the gene mutated in DMD.
Asunto(s)
Proteínas Musculares/biosíntesis , Distrofias Musculares/metabolismo , Proteínas Quinasas , Anticuerpos Monoclonales/inmunología , Niño , Preescolar , Deleción Cromosómica , Conectina , Humanos , Masculino , Proteínas Musculares/genética , Proteínas Musculares/inmunología , Músculos/análisis , Distrofias Musculares/genética , Cromosoma XRESUMEN
We found that eight of 22 patients with meningeal carcinomatosis from different primary tumors produced local IgG in the CSF, as indicated by elevated IgG index and/or oligoclonal IgG subfractions. Local IgG production, when present, appears in an early stage of the leptomeningeal manifestation and remains detectable over extended observation periods. In autopsied cases with local IgG production, we observed numerous perivascular round-cell infiltrates containing plasma cells and large lymphocytes within the leptomeningeal tumor tissue. After incubation with immunoperoxidase, only these cells showed IgG-specific staining, indicating the site of local IgG production.
Asunto(s)
Carcinoma/líquido cefalorraquídeo , Inmunoglobulina G/líquido cefalorraquídeo , Neoplasias Meníngeas/líquido cefalorraquídeo , Adulto , Anciano , Carcinoma/patología , Carcinoma/secundario , Femenino , Humanos , Inmunoglobulinas/líquido cefalorraquídeo , Masculino , Neoplasias Meníngeas/patología , Neoplasias Meníngeas/secundario , Persona de Mediana Edad , Bandas OligoclonalesRESUMEN
Sixteen patients suffering from hemicranial attacks are reported. After many years of unsuccessful conservative treatment (mean = 12.4 years), the patients were treated surgically with good results. The radiological or electrophysiological examinations were non-specific or negative. Only vasoactive tests (provoking or relieving pain) or local anesthesia proved helpful in diagnosing and localizing the origin of pain. Intraoperatively, hemicranial attacks were found to be caused by vascular irritation or compression of the cervical nerve root C2. After decompression (n = 6) or dissection (n = 10) of the nerve root and the ganglion, 12 patients were relieved of their pain, 2 had improved relatively, 1 showed only a slight improvement, and in 1 patient no cause was found and no improvement was achieved. Two patients suffered recurrence of pain postoperatively; one had no further complaints after root extirpation following percutaneous thermorhizotomy. Electron microscopic examination of the nerve root and its ganglion revealed focal morphological changes, including proliferation of connective tissue in the endoneurium and the ganglion itself, the formation of onion-bulb-like structures around single axons, discrete signs of myelin damage and axonal degeneration. These morphological changes are possibly the result of a chronic vascular compression.
Asunto(s)
Lateralidad Funcional/fisiología , Cefalea/fisiopatología , Raíces Nerviosas Espinales/fisiopatología , Adulto , Femenino , Cefalea/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Raíces Nerviosas Espinales/irrigación sanguínea , Raíces Nerviosas Espinales/cirugíaRESUMEN
Biotinylated heparin has been used to detect the presence of specific binding sites in sections of human placenta, which has prompted demonstration of expression of lectin activity for this proteoglycan. Purification of this lectin from full-term placenta facilitates the synthesis of its biotinylated derivative, using biotin-amidocaproyl hydrazide, without affecting its activity. It also enables immunization to obtain antibodies. The labeled lectin is shown to bind specifically to nuclear and cytoplasmic locations in various cell types of human placenta, nuclear expression of lectin binding sites being more pronounced at the full-term stage than after 8 weeks of development. The structurally related histone H2B exhibits obvious differences in its binding pattern. The presence of ligands accessible to the lectin whose binding activity can be inhibited by addition of an excess of heparin correlates in most instances with the level of lectin expression detected immunohistochemically. Biochemical information on the nature of the glycohistochemically inferred lectin-specific ligand(s) is obtained by affinity chromatography on resin-immobilized lectin. It leads to isolation of a proteoglycan with similar electrophoretic mobility in agarose-polyacrylamide gel electrophoresis relative to the independently purified heparan sulfate-containing fibronectin binding proteoglycan from human placenta. Both fractions inhibit binding of heparin to the lectin and contain immunologically detected co-purified lectin, emphasizing their ligand properties. Application of labeled tissue lectins in conjunction with lectin-specific antibodies is proposed to obtain valuable insights into the expression of the receptor as well as the ligand part of protein-carbohydrate recognition.
Asunto(s)
Heparina/metabolismo , Lectinas/metabolismo , Placenta/metabolismo , Receptores Mitogénicos/análisis , Cromatografía de Afinidad , Electroforesis/métodos , Femenino , Histocitoquímica , Humanos , Ligandos , Embarazo , Unión Proteica , Proteoglicanos/metabolismoRESUMEN
A panel of biotinylated (neo)glycoproteins was used for specific detection of endogenous sugar receptors, especially lectins, in formaldehyde-fixed, paraffin-embedded muscle biopsy specimens from human deltoid, quadriceps, and biceps muscles, tibial and quadriceps muscles of rat, and bovine masseter muscle. The glycohistochemical probes used consisted of conjugates of a labeled, histochemically inert carrier protein and various covalently linked, histochemically crucial sugar moieties. Specific binding of alpha-L-fucoside, beta-D-galactoside, beta-D-xyloside, and alpha-D-mannoside to muscle sections was detected, showing no species-specific differences. The presence of receptors for the N-acetylated sugars in natural glycoconjugates, and for sugars with a phosphate group, i.e., mannose-6-phosphate and galactose-6-phosphate, was demonstrated glycohistochemically. However, these binding specificities revealed species-specific differences, e.g., the absence of N-acetyl-D-galactosamine-specific receptors or galactose-6-phosphate-specific receptors in rat muscle. Other charged sugars included glucuronic acid and sialic acid, which bound only to ox and rat muscle or failed to reveal their respective receptors in all types of muscle investigated. This different extent of staining with anionic probes served as a further control to ascertain carbohydrate binding specificity. Positive glycohistochemical reaction developed within sarcomeres only at the level of A-bands. Granular staining was observed in the sarcoplasm among the myofibrils and also in the subsarcolemmal regions. Differences in expression of glycohistochemically detectable sugar receptors were noted between type 1, type 2A, and type 2B fibers. The molecular properties of one type of glycohistochemically detectable sugar receptor were inferred both immunohistochemically and biochemically. An antiserum against an endogenous beta-galactoside-specific lectin from muscle tissue localized this lectin within sections consistently similar to (neo)glycoproteins, detecting beta-galactoside-specific receptor(s). This similarity of binding patterns strongly supports the assumption that (neo)glycoproteins with beta-galactoside termini indeed bind to the respective endogenous lectin. The lectin-specific antiserum enabled us to ascertain that glycohistochemical fiber typing corresponds to enzyme histochemical typing. Moreover, biochemical purification using affinity chromatography and subsequent affinity elution revealed only the immunohistochemically detectable beta-galactoside-specific lectin. Consequently, use of a panel of neoglycoproteins, when frozen sections for histochemical analysis are not available, co
Asunto(s)
Músculos/análisis , Complejo GPIb-IX de Glicoproteína Plaquetaria , Glicoproteínas de Membrana Plaquetaria , Receptores Inmunológicos/análisis , Receptores Mitogénicos/análisis , Acetilación , Animales , Asialoglicoproteínas/metabolismo , Bovinos , Cromatografía de Afinidad , Fijadores , Formaldehído , Fucosa/metabolismo , Galactósidos/metabolismo , Glucuronatos/metabolismo , Ácido Glucurónico , Glicósidos/metabolismo , Histocitoquímica , Humanos , Inmunohistoquímica , Manosa/metabolismo , Ácido N-Acetilneuramínico , Parafina , Fosfatos , Ratas , Ratas Endogámicas , Receptores Inmunológicos/metabolismo , Ácidos Siálicos/metabolismo , Especificidad de la EspecieRESUMEN
A family is reported in which two members presented with proximal myopathy associated with high serum levels of angiotensin-converting enzyme (SACE), creatine kinase (CK), and lactate dehydrogenase isoenzyme 5. Examination of three relatives revealed elevated SACE levels in all of them, but no myopathy. No evidence of sarcoidosis, the most common disease associated with high SACE levels, could be found. Muscle biopsies of the two affected men revealed myopathic features without granuloma formation. Extensive biochemical, metabolic, immunological, and microbiological studies were all non-contributory. Corticosteroid and, in one patient, azathioprine treatment resulted in an improvement of muscle weakness and in a decrease of SACE as well as CK levels.
Asunto(s)
Pruebas Enzimáticas Clínicas , Enfermedades Musculares/diagnóstico , Adulto , Creatina Quinasa/sangre , Electromiografía , Familia , Femenino , Humanos , Isoenzimas , L-Lactato Deshidrogenasa/sangre , Masculino , Persona de Mediana Edad , Músculos/ultraestructura , Enfermedades Musculares/etiología , Enfermedades Musculares/inmunología , Enfermedades Musculares/patología , Linaje , Peptidil-Dipeptidasa A/sangreRESUMEN
Small separated accessory ventricles in the occipital lobe were observed in 21.3% of 404 patients, as seen by computerized tomogram. There was no significant preponderance in regard to sex or laterality. The accessory ventricles were clinically not significant. As seen at autopsy, accessory ventricles were found in the subcalcarine white matter, posterior to the occipital horn of the lateral ventricle, in 29.5% of 200 "normal" brains. Again, there were no significant sex and laterality differences. Accessory ventricles were never found in brains of fetuses or newborn babies. The youngest child in whom an accessory ventricle was found was 1 month old. No accessory ventricles were larger than 1 cm in diameter; they were slit-like, triangular or oval in shape. Histologically, they showed subtotal loss of the ependymal layer, subependymal gliosis, and/or fibrosis, and, in some cases, hyalinofibrotic capillary degeneration. Electron microscopy of the remaining ependymal cells in the accessory ventricle showed marked atrophy. Accessory ventricles are formed at the tip of the occipital horn postnatally through the expansion of the deep calcarine fissure, increase in brain volume in the region, and subsequent fusion of the mediolateral ventricular walls.
Asunto(s)
Ventrículos Cerebrales/anomalías , Lóbulo Occipital/anomalías , Adolescente , Adulto , Anciano , Ventrículos Cerebrales/patología , Ventriculografía Cerebral , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Lóbulo Occipital/diagnóstico por imagen , Lóbulo Occipital/patologíaRESUMEN
The carbohydrate part of cellular glycoconjugates - glycoproteins, glycoproteins, glycolipids and proteoglycans - and specific endogenous sugar receptors, i.e. lectins, can establish a system of biological recognition based on protein-sugar interactions on the cellular and subcellular levels. To gain insight into the role of proteins in this type of interaction, sections of surgically removed tumor specimens of central and peripheral nervous tissue were analyzed glycohistochemically, using biotinylated neoglycoproteins with different sugar part. A specific staining with this type of probe, exposing different sugar moieties as ligands, indicated the presence of sugar receptors in different types of meningiomas, glioblastomas, gangliocytomas, anaplastic and well-differentiated oligodendrogliomas and ependymomas as well as in neurinomas and neurofibromas of peripheral nerves. In comparison to the well-differentiated ependymomas, the anaplastic form of this tumor exhibited a generally higher capacity to specifically bind the neoglycoproteins, containing alpha- or beta-glucosides. Inverse intensity of the glycohistochemical reaction was observed with galactose-6-phosphate-, galactose-beta(1.3)-N-acetylglucosamine-N-acetyl-D-glucosamine- and mannose- (BSA- biotin), respectively, when anaplastic and differentiated oligodendrogliomas were compared with each other. Tumorously dedifferentiated neurons, i.e. in gangliocytomas, showed a changed spectrum of endogenous sugar receptors in comparison to neurons of normal cerebral cortex. Qualitative and quantitative differences of sugar receptors were observed among the distinct subtypes of meningiomas. Receptors for N-acetyl-D-galactosamine were present only in the anaplastic form, while glucuronic acid-specific receptors were only found in the meningotheliomatous meningiomas. Distinctions in binding spectrum of neoglycoproteins suggest the presence of a possible additional subtype of meningiomas, called submalignant meningioma. Analysis of the spectrum of endogenous sugar receptors can serve to distinguish between different cell populations composing a given tumor, as shown in neurofibromas in the cases of Schwann cells and fibroblastoid cells stained with N-acetyl-D-glucosamine-(BSA-biotin). The analysis of expression of endogenous sugar receptors, as part of an intercellular information code system, may represent a further way of studying the mechanism of tumor differentiation and propagation.
Asunto(s)
Biotina , Proteínas Portadoras/análisis , Glicoproteínas , Lectinas/análisis , Neoplasias del Sistema Nervioso/química , Receptores de Superficie Celular , HumanosRESUMEN
A 4-year-old boy with a history of muscular hypotonia, mental retardation, microcephaly, and generalized convulsions was found at autopsy to have agyria, agenesis of the anterior commissure and posterior corpus callosum as well as an abnormal decussation of pyramidal tracts which descended in the spinal dorsal columns. Postmortem muscular alterations included type IIc fiber hypertrophy and type I fiber grouping, variably expressed in individual muscles and intramuscular fascicles. This may represent a developmental delay compatible with a gestational age between the 34th and 40th week. These studies also indicate the importance of examining multiple samples of postmortem muscles and muscles from patients afflicted with cerebral malformations.
Asunto(s)
Corteza Cerebral/anomalías , Músculos/patología , Tractos Piramidales/anomalías , Preescolar , Humanos , MasculinoRESUMEN
Ultrastructural and enzyme histochemical muscle abnormalities are described in a case with a new variant (type Homburg) of glucosephosphate isomerase (GPI) deficiency, associated with congenital nonspherocytic hemolytic anemia and muscle weakness. The enzyme is thermostable in contrast to other described variants. The muscle fibers showed decreased GPI activity, ultrastructural abnormalities, including giant mitochondria, and a diffuse increase of glycogen. The functional alteration of muscle tissue is due to a stable enzyme protein with decreased specific activity.
Asunto(s)
Anemia Hemolítica Congénita no Esferocítica , Músculos/ultraestructura , Adolescente , Biopsia , Glucosa-6-Fosfato Isomerasa/metabolismo , Histocitoquímica , Humanos , Masculino , Microscopía Electrónica , Músculos/metabolismoRESUMEN
An adult patient with micrencephaly combined with unusual multiple glioneural leptomeningeal heterotopias is presented. In spite of the large number of leptomeningeal heterotopias supra- and infratentorially, the cortices of the cerebrum and the cerebellum were well-organized and the white matter was well-myelinated. The heterotopias contained glial tissue and mature neurons, those in the cerebellum resembling Purkinje cells and granular cells, along with axons and mineralizations. The pathogenesis of the leptomeningeal heterotopias and micrencephaly is discussed.
Asunto(s)
Neoplasias Encefálicas/patología , Encéfalo/anomalías , Coristoma/patología , Meninges , Adulto , Encéfalo/patología , Femenino , HumanosRESUMEN
The clinical picture of Morvan's fibrillary chorea includes a. spontaneous muscular activity resulting from repetitive motor unit action potentials of peripheral origin (multiplets), b. autonomic dysregulation with profuse hyperhidrosis, and c. central nervous system involvement as shown by severe insomnia and hallucinosis. A case featuring all these symptoms is presented. Whereas known causative factors range from gold or mercury poisoning to autoimmune disorders, the presented case is the first one in which chronic manganese intoxication (occupational exposure) seems to be implicated. Manganese has been found to inhibit acetylcholine esterase, and, as a consequence, may produce peripheral and central cholinergic hyperactivity.
Asunto(s)
Corea/inducido químicamente , Intoxicación por Manganeso , Anciano , Corea/complicaciones , Corea/diagnóstico , Corea/patología , Humanos , MasculinoRESUMEN
The ultrastructure of normal human facial muscles from 25 nonparalytic and 17 paralytic patients revealed normal features in nondenervated human facial muscles, identical to the fine structure of other normal human and mammalian cross-striated muscle fibers. However, in denervated facial muscle, a broad spectrum of ultrastructural lesions had affected sarcomeres, abnormal inclusions, and organelles. A large variety of inclusion bodies, some of which have not been described, were also found. The spectrum of ultrastructural changes showed no dependence on the length of the denervation period. There were no inclusion bodies in all the normal facial muscle biopsies. To our knowledge, this study represents the first systematic electron microscopic investigation of normal and denervated human facial muscles.
Asunto(s)
Músculos Faciales/ultraestructura , Adolescente , Adulto , Anciano , Membrana Basal/ultraestructura , Músculos Faciales/cirugía , Nervio Facial/cirugía , Parálisis Facial/cirugía , Femenino , Humanos , Cuerpos de Inclusión/ultraestructura , Masculino , Microscopía Electrónica/métodos , Persona de Mediana Edad , Desnervación MuscularRESUMEN
Protein-carbohydrate recognition has been found to play an important role in phagocytosis. Labelled (neo)glycoproteins were employed to comparatively analyze the histochemical pattern and ultrastructural localization of endogenous carbohydrate-binding proteins (lectins) of mononuclear macrophages and multinucleate giant cells involved in the granulomatous foreign body reaction. Sugar receptors having an affinity to simple alpha- and beta-galactoside-structures, to alpha-mannose residues, to N-acetylglucosamine, to N-acetylgalactosamine and to glucuronic acid, respectively, were detected in both cell types. However, alpha-fucoside- and beta-xyloside-specific receptors were present only in the mononuclear macrophages. Pronounced differences were seen with labelled, suitably modified glycoproteins, exposing different complex sugar parts with common beta-galactoside-termini. Among the population of multinucleate giant cells, a positive histochemical reaction was observed with mannose-6-phosphate-, galactose-6-phosphate- and glucuronic acid-(BSA-biotin), respectively, only in giant cells in which fusing mononuclear cells were recognizable. This transient expression indicates changes within the profile of endogenous sugar receptors in the stages from fusion to establishment of giant cells. Aside from the diffuse intracytoplasmic distribution of carbohydrate-binding proteins, a prominent accumulation of various types of glycosylated ferritin, used as a marker for electron microscopic evaluation, was ultrastructurally found in membranous subcellular structures and vesicles. This study is a basis for further investigation of the potential involvement of various sugar receptors in the process of macrophage fusion, resulting in multinucleate giant cells of foreign body type, and the process of phagocytosis.
Asunto(s)
Núcleo Celular/ultraestructura , Glicoconjugados/fisiología , Macrófagos/citología , Receptores de Superficie Celular/fisiología , Biopsia , Metabolismo de los Hidratos de Carbono , Fusión Celular , Ferritinas , Glicoproteínas , Granuloma de Células Gigantes/metabolismo , Granuloma de Células Gigantes/patología , Histocitoquímica , Humanos , Lectinas/metabolismo , Macrófagos/metabolismo , Macrófagos/ultraestructura , Microscopía Electrónica , Fagocitosis , Receptores de Superficie Celular/metabolismoAsunto(s)
Glicoproteínas , Histocitoquímica , Complejo GPIb-IX de Glicoproteína Plaquetaria , Glicoproteínas de Membrana Plaquetaria , Glicoproteínas/síntesis química , Glicoproteínas/química , Glicoproteínas/metabolismo , Glicosilación , Lectinas/análisis , Neoplasias , Receptores Inmunológicos , Distribución TisularRESUMEN
Two proximal branches of the rat facial nerve were transected and anastomosed end-to-end within a silicone tube, each of them being exposed to a massive invasion of ascending regenerating axons. The proximal nerves contained extremely large bundles of regenerated fibers, often associated with preexistent "parent fibers." The bundles showed many signs of rash and disordered cell proliferation and myelination. These included multiple Schwann cells surrounded by a common basement membrane, occurrence of different phases of myelination and even myelination of two axons by one Schwann cell. There was no evidence of mitogenic signals for fibrocytes. This model may be used for studying the mitogenic effect of axons on Schwann cells. It also suggests that so-called "groups of regenerating fibers" in neuropathy are caused by Schwann cell recruitment.
Asunto(s)
Nervio Facial/citología , Fibras Nerviosas/fisiología , Regeneración Nerviosa , Células de Schwann/fisiología , Animales , División Celular , Nervio Facial/fisiología , Microscopía Electrónica , Modelos Neurológicos , Vaina de Mielina/fisiología , Vaina de Mielina/ultraestructura , Fibras Nerviosas/ultraestructura , Fibras Nerviosas Mielínicas/fisiología , Fibras Nerviosas Mielínicas/ultraestructura , Ratas , Ratas Endogámicas , Células de Schwann/citologíaRESUMEN
For attaching histological sections to slides a new adhesive medium consisting of rubber silicon is described. Using this substance the damage to histological sections caused by various techniques and enzyme digestion (floating) may be eliminated. This method can be applied both to paraffin and frozen sections.
Asunto(s)
Técnicas Histológicas , Adhesivos , Secciones por Congelación , Humanos , Parafina , Elastómeros de SiliconaRESUMEN
Mycotic oesophagitis can be divided into two major groups: the less frequent primary form occur without any predisposing disease and the secondary one developing more frequently as a result of predisposing diseases or pathologic processes of the oesophagus. In the case reported differential-diagnostic problems of the secondary mycotic oesophagitis are discussed. The primary lesion in this case was leiomyosarcoma of the oesophagus which remained undetected by the four biopsies performed. The specimen obtained in each occasion consisted of necrotic-mycotic material. Stenosis of the oesophagus caused by the tumour, prevented the successful biopsy.