Liver rejection and its differentiation from other causes of graft dysfunction

Numerous causes can lead to hepatic dysfunction following orthotopic liver transplantation. The most common cause is rejection, which is usually nonpreventable. The clinical presentation, time of onset, and even treatment are variable. Other causes, such as perioperative ischemic injury, vascular thrombosis, and complications of bile duct reconstruction may be preventable with good surgical technique. Infections can also be minimized by careful adjustment of immunotherapy, avoidance overimmunosuppression, and the judicious use of antibiotics. Hepatic dysfunction following orthotopic liver transplantation requires rapid assessment and proper treatment in order to prevent serious and possibly fatal complications.

Endocervical stromal sarcoma--a case report

A case of a stromal sarcoma in a cervical polyp is presented. The tumor was confined to the polyp as evidenced by the histological examination of the uterus and cervix after surgery. In spite of that the patient died of widespread abdominal metastasis 1 year after the initial diagnosis.

Gynecologic masses: value of magnetic resonance imaging

Forty-two women with gynecologic abnormalities were studied with the use of magnetic resonance imaging. Magnetic resonance imaging correctly assessed the origin of the pelvic mass in all patients. In the evaluation of leiomyoma, magnetic resonance imaging accurately depicted the number, size, and location of the lesion. In the evaluation of endometrial carcinoma, magnetic resonance imaging depicted the location of the lesion, the presence of cervical extension, and the depth of myometrial penetration in the majority of the cases. In the analysis of adnexal cysts, magnetic resonance imaging was sensitive in localizing the lesion and was able to distinguish serous from hemorrhagic fluid. This preliminary report indicates that magnetic resonance imaging may become a valuable imaging modality in the diagnosis of gynecologic abnormalities.

Placental chorioangiomatosis--a high risk pregnancy

A case of diffuse chorioangiomatosis leading to fetal hydrops, disseminated intravascular coagulopathy with massive umbilical vein thrombosis and fetal death is described. Although rare, this benign mesenchymatous malformation of the placenta should be kept in mind as a possible cause of neonatal morbidity. Prenatal diagnosis could prevent fetal death.

Characteristics of receptors and enzymes in brains of human alcoholics

Acute and chronic ethanol administration to animals has been shown to produce changes in the turnover of numerous neurotransmitters, as well as to change the characteristics of certain neurotransmitter receptors. In the present study, brains obtained from human alcoholics and matched control subjects were examined for similar changes. In frontal cortex, the affinity of opiate receptors for dihydromorphine was significantly reduced in brains of alcoholics. Judging from animal studies, this change may reflect alterations in opiate receptor-effector coupling processes. No changes were observed in muscarinic cholinergic or beta-adrenergic receptors in humans, in contrast to animals, possibly because of the protracted abstention from alcohol among the alcoholic patients prior to death. Similarly, no changes in the activities of choline acetyltransferase, tyrosine hydroxylase or MAO-B were observed in brains of alcoholics as compared to the control population. Our studies suggest that many of the alterations witnessed during alcohol intoxication and withdrawal in animals may be more subtle in humans, or may be reversible with abstinence.

Bromocriptine as primary therapy for prolactin-secreting macroadenomas: results of a prospective multicenter study

To assess the effectiveness of bromocriptine in reducing the size of PRL-secreting macroadenomas with extrasellar extension, we conducted a prospective multicenter trial in patients without prior radiotherapy, applying a standard protocol of treatment and tumor size evaluation. Basal serum PRL levels [1441 +/- 417 (+/- SEM) ng/ml for women; 3451 +/- 1111 ng/ml for men] fell in all patients and to 11% or less of basal values in all patients but 1. Normal PRL levels were reached in 18 of the 27 patients. In 13 patients (46%), tumor size was reduced by greater than 50%, in 5 patients (18%) by about 50%, and in 9 patients (36%) by approximately 10-25%. The extent of tumor size reduction did not correlate with basal PRL, nadir PRL, percent fall in PRL, or whether PRL levels reached normal. However, a reduction in PRL levels always preceded any detectable change in tumor size. In 19 patients, reduction in tumor size was evident by 6 weeks, but in the other 8, such reduction was not noted until the 6 month evaluation. In the 4 patients in whom bromocriptine was discontinued at the end of 1 yr, tumor reexpansion occurred in 3. Visual fields improved in 9 of the 10 patients in whom they were abnormal. Because of the excellent results found in most of the patients in this series, we suggest that therapy with bromocriptine should be considered as initial management for patients with PRL-secreting macroadenomas.

Fetal supraventricular tachycardia: prenatal diagnosis and pharmacological reversal of associated hydrops fetalis

Intrauterine fetal supraventricular tachycardia is a rare condition often associated with the syndrome of nonimmune hydrops fetalis. When the fetus is preterm it is vital to treat the arrhythmia with maternally administered drugs and different regimens have been reported in the literature. We report 1 case of this arrhythmia successfully treated in utero with maternally administered digoxin resulting in complete reversal of the hydrops fetalis and the birth of a healthy baby. A review of the relevant literature is brought forth.

Prophylactic single-dose co-trimoxazole for prevention of urinary tract infection after abdominal hysterectomy

The efficacy of a preoperative single-dose of co-trimoxazole in reducing postoperative urinary tract infection and febrile morbidity after abdominal hysterectomy was evaluated in a randomized placebo-controlled study of 90 patients undergoing surgery. Among the co-trimoxazole patients, 6.2% developed urinary tract infection compared to 31% in the placebo group (p less than 0.001) and 12.5% febrile morbidity compared to 38% in the placebo patients (p less than 0.025). No adverse side effects of co-trimoxazole were observed and this regimen seems both safe and effective.

The neuroectodermal tumor of bone

Four small round cell malignant tumors of bone occurring in children are described. There was no catecholamine secretion and the clinical, radiologic, and biopsy diagnosis in each was Ewing's sarcoma. Glycogen was sparse both on imprints and in tissue sections. The tumors, when extensively sampled, had areas of a lobular growth pattern and Homer Wright rosettes. The rosettes were always focal and varied in complexity from case to case; they were rudimentary in one instance and markedly fibrillar in the most obvious instance. Neuron-specific enolase was demonstrated in tissue sections and in longterm cell cultures from three of the tumors. The cultured cells put out moderately long beaded processes in serum-free medium but had no catecholamine fluorescence. Electron microscopy of the tumor rosettes and the cultured cells showed processes containing aggregates of microtubules and only one case had rare neurosecretory granules. This study suggests that some small round cell tumors of bone and soft tissue in children, which present as Ewing's sarcoma, are neuroectodermal in nature.

Segmental staining of the murine nephron by monoclonal antibodies directed against the GP-2 subunit of laminin

Monoclonal antibodies to GP-2, the 220,000-dalton subunit of laminin, were used in an immunohistologic study to investigate structural variations in basement membranes. Mouse kidney was used because of the wide range of basement membranes represented. Two rat/mouse monoclonal antibodies, designated LAM-I and LAM-II were compared with rabbit polyclonal anti-GP-2 in a light and electron microscopic study that identified nephron segments by morphology, by topography, and by the use of markers specific for individual segments. LAM-I staining is demonstrable on all tubular and glomerular basement membranes but not on those of blood vessels or smooth muscle, differing in this respect from anti-GP-2. LAM-II staining is confined to the basement membranes of the convoluted portion of proximal tubule segments (S1 and S2), not the straight (S3) portion; to the thin limb and the thick ascending limb of Henle's loop, but not distal convoluted tubules or collecting ducts. The heterogeneity of GP-2 localization may be due to differing conformations of the molecule at these sites.

Flexible fiberoptic sigmoidoscopy in family medicine

Flexible fiberoptic sigmoidoscopy is easily mastered by family physicians. Self-study, along with a minimal amount of supervision, seems to provide adequate training. Patient preparation is essential and is best accomplished with enemas "until clear" rather than with the standard two enemas. Patients prefer the flexible sigmoidoscope to the rigid instrument, and the greater depth of penetration achieved with the former--even with the 35-cm sigmoidoscope--enables the physician to detect significantly more pathologic lesions.

Tumor radioimmunolocation: differential antibody retention by antigenic normal tissue and tumor

On the assumption that a high specificity would be required for in vivo tumor location and drug targeting, much labor has been expended to produce monoclonal antibodies directed to antigens found primarily on tumors. However, for at least one tumor-associated antigen, stage-specific embryonic antigen 1 (SSEA-1), the concentration of the target antigen need not be higher in the tumor than that found in normal tissues for successful use of the corresponding monoclonal antibody in in vivo tumor location; rather, accessibility and antibody metabolism are more important.

Tumor radioimmunolocation: differential antibody retention by antigenic normal tissue and tumor

On the assumption that a high specificity would be required for in vivo tumor location and drug targeting, much labor has been expended to produce monoclonal antibodies directed to antigens found primarily on tumors. However, for at least one tumor-associated antigen, stage-specific embryonic antigen 1 (SSEA-1), the concentration of the target antigen need not be higher in the tumor than that found in normal tissues for successful use of the corresponding monoclonal antibody in in vivo tumor location; rather, accessibility and antibody metabolism are more important.

Ultrasonic screening in predicting the time of ovulation

A consistent sign of imminent ovulation in the graafian follicle has been observed by ultrasonic screening. The sign is the appearance of a double contour along the follicle wall, with the wall losing its clear appearance. This is an important sign which can be used in all programs in which the exact timing of ovulation is important, in order to receive the best possible results in treatment of infertility.

Monoclonal antibodies against the GP-2 subunit of laminin

Two stable rat X mouse hybridoma lines have been isolated. These hybridoma lines produce IgG antibodies directed against the polypeptide portion of the GP-2 subunit of laminin. Antibodies produced by the hybridomas have been shown to be IgG 2b (lambda) and IgG 2a (kappa), respectively. In competition ELISA assays the monoclonal antibodies exhibited different binding affinities for laminin. Furthermore, the two antibodies were partially additive in their reactivity to laminin. Preliminary results also indicate that the antibodies recognized different antigenic determinants in laminin as determined by their reactivity to basement membranes in human and mouse tissues. The monoclonal antibody designated LAM-I stained a broad spectrum of human and mouse tissues; the other monoclonal antibody LAM-II reacted with mouse, but not human tissues. The results indicate that these monoclonal antibodies could be utilized to explore the organization of laminin in basement membranes of different tissues and species.

Selective fetal malnutrition: the effect of in vivo ethanol exposure upon in vitro placental uptake of amino acids in the non-human primate

In vitro uptake (45 and 90 minutes) of amino acids, alpha-amino isobutyric (AIB) and valine (VAL), was measured in six placentae from the nonhuman primate, Macacca fascicularis. Three of the pregnant primates were chronically treated with ethanol before and throughout pregnancy (CHR); one during the last trimester only (LT); and two were controls (C). Compared to the C placentae, the LT placenta had significantly decreased uptake only for AIB at 45 min: 33.4 +/- 6.8% reduction (mean +/- S.E.) (P less than 0.05). In contrast, the CHR placentae demonstrated significantly reduced uptake (P less than 0.01) for both amino acids at both time points. Percent reduction at 45 and 90 min: AIB, 35.2 +/- 6.5% and 32.6 +/- 5.6% and VAL, 38.7 +/- 2.9% and 22.1 +/- 4.1%. The results indicate that chronic in vivo ethanol exposure impairs the in vitro placental uptake of two actively transported amino acids, using an animal with a placenta almost identical to the human.

Synthesis of laminin and entactin by F9 cells induced with retinoic acid and dibutyryl cyclic AMP

Mouse embryonal carcinoma F9 cells were exposed to retinoic acid and dibutyryl cyclic AMP. The treated cells synthesized and secreted into the culture medium the basal lamina components, laminin (GP-1 and GP-2) and entactin. The time course of secretion of the basal lamina components was examined by electron microscopic and immunochemical procedures. The induction of the cells resulted in major morphological changes and the deposition of both laminin and entactin at the cell surface and cell junctions. Intracellular deposits of laminin could be localized to the endoplasmic reticulum and membrane-bound intracytoplasmic vacuoles. Concomitant with the appearance of laminin and entactin, there was a loss of fibronectin synthesis and a marked decrease in a 190,000-Da sulfated glycoprotein that appeared to be related to entactin. In the induced cells, laminin and entactin were associated in a complex that could be dissociated with low concentrations of sodium dodecyl sulfate. The induction of laminin and entactin seem to be independent. The enhanced synthesis of laminin appeared to be under transcriptional regulation since it was found that induced F9 cells contained translatable mRNA for GP-2 when tested in a rabbit reticulocyte lysate system. The uninduced cells did not contain detectable quantities of translatable GP-2 mRNA.

Congenital Budd-Chiari syndrome

Budd-Chiari syndrome, due to thrombotic occlusion of hepatic veins or ostia, is unusual in infants. Review of the literature reveals no documented case symptomatic at birth. We describe a male infant with ascites present at birth. A liver biopsy at 7 weeks of age showed sinusoidal dilatation, but the diagnosis of Budd-Chiari syndrome was made only at autopsy, 4 months later. The cause was not determined although maternal drug abuse was suspected.

Pancreatic pathology in trisomy 13: specificity of the morphologic lesion

Pancreases from 8 patients with trisomy 13 were studied. Ectopic splenic tissue was present in 6: 3 had accessory spleens and ectopic splenic tissue embedded in the pancreas, one had intrapancreatic splenic tissue without an accessory spleen, and one had an accessory spleen without intrapancreatic splenic tissue. The intrapancreatic splenic tissue was multiple, generally poorly or nonencapsulated, and contained pancreatic acini, islets of Langerhans, and ducts lined by tall columnar epithelium with goblet cells. The rest of the pancreas in these and other cases of trisomy 13 had microcyst formation and focal proliferations of small ducts similar to those seen in the splenic tissue. This constellation of features appears to be distinctive of trisomy 13.

Development of renal basement membrane glycoproteins in metanephric organ culture

Because of the importance of renal basement membrane glycoproteins in normal and abnormal tubular and glomerular morphogenesis, structure, and function, the sequential development of fibronectin, GP-2, and entactin was studied in vivo and in a newly developed, serum-free mouse metanephric organ culture system. The organ culture system permits advanced tubular differentiation and glomerular epithelial development of whole metanephros without perfusion or urine formation. Affinity-purified antibodies and immunohistologic techniques were used, and the ontogeny of basement membrane glycoproteins was characterized in vivo and in vitro. It was thus possible to characterize the pattern of normal renal basement membrane glycoprotein production and to comparatively study renal glomerular and tubular basement membrane formation in the presence and the absence of endothelial and/or mesangial influences. Both in vivo and in vitro undifferentiated mesenchyme expressed fibronectin but not GP-2 or entactin. Further, both in vivo and in vitro, all three glycoproteins developed in the basement membranes of the earliest recognizable tubular and glomerular forms. Because of the sharp parallel between in vivo and in vitro basement membrane glycoprotein production we conclude that the whole organ metanephric culture system is a useful model for the study of renal basement membrane development. Further, based on the pattern of in vitro basement membrane production, it may be concluded that tubular and glomerular epithelial cells are capable of producing basement membrane glycoproteins in the absence of endothelial or recognizable mesangial cells following initial embryonic induction.

Flexible fiberoptic sigmoidoscopy

The 35-cm flexible fiberoptic proctosigmoidoscope is a cost-effective instrument for the family physician. Nonendoscopists have mastered its use with no reported complications. Patient tolerance is high compared to tolerance for the rigid scope. The pathology yield per procedure is two to four times greater than that reported with the rigid sigmoidoscope. Yields with the 35-cm instrument have matched those documented with the 65-cm fiberoptic instrument.

Cryotherapy in ankle sprains

This study assesses recovery from ankle sprains. Thirty-seven final participants were categorized according to the severity of their injury and the use of cryotherapy (15 minutes, one to three times per day) versus heat therapy (15 minutes, one to three times per day) for a minimum of three days. Therapy commenced either less than one hour, from one to 36 hours, or greater than 36 hours after traumatic event. Sprains were graded into five categories based on severity of the injury, but only two categories, subject to conservative treatment, are considered in this study. The study showed that cryotherapy started within 36 hours after the injury was statistically more effective than heat therapy for complete and rapid recovery. Patients in a group with Grade four sprains (unable to bear weight because of pain) reached full activity in 13.2 days compared to 30.4 days in a group using cryotherapy initiated 36 hours after injury or to 33.3 days in a group using heat therapy. Therefore, early use of cryotherapy, continued with adhesive compression, is an effective treatment of ankle sprains yielding earlier complete recovery than late cryotherapy or heat therapy.

Metanephric development in serum-free organ culture

A new mouse metanephric organ culture system has been developed to study mammalian renal development. The system permits in vitro organotypic differentiation in a serum-free, hormone supplemented medium consisting of Dulbecco's minimal essential medium (MEM) and Ham's F12 medium supplemented with insulin, 5 microgram/ml; PGE1, 25 ng/ml; T3, 3.2 pg/ml; hydrocortisone, 5 microgram/ml; and transferrin, 5 microgram/ml. In this system, metanephric development continues morphologically beyond the S-shaped tubule stage. A well differentiated proximal tubule forms with a well defined brush border, specialized intercellular connections, and an apical endocytic network. In addition, a unique devascularized glomerulus, with highly differentiated podocytes surrounding areas of basement membrane, forms entirely from epithelial elements. The present organ culture model goes beyond the limitations of previously described systems in that it does not require separation of nephrogenic blastema from ureteric bud, nor require animal serum or nonspecific tissue extracts for metanephric development. The model is thus suited for morphological, biochemical, and endocrinological study of normal and abnormal renal organogenesis.

Neonatal adrenoleukodystrophy: clinical, pathologic, and biochemical delineation of a syndrome affecting both males and females

We describe the detailed clinical, pathologic, and biochemical features of brother and sister with the neonatal onset form of adrenoleukodystrophy, together with evidence of the biochemical defect. When compared with reports of previous cases, it becomes clear that this is a newly described clinical entity with remarkable uniformity of signs and very different from the usual childhood form. Some pathologic features are shared, including the morphologic abnormality of the adrenal in both neonatal and childhood forms, but deposition of abnormally metabolized lipids is more systemic and widespread in the neonatal form. The biochemistry of the disease is presented in both children and parents. Plasma values of long-chain fatty acid C26:0 are 0.328 +/- 0.18 micrograms/ml in a control population and 0.381 +/- 0.312 micrograms/ml in the father and mother. Values for C26:0 in the plasma of childhood adrenoleukodystrophy are 1.62 +/- 0.87 micrograms/ml and in our two cases, 2.79 micrograms/ml in the male, 1.83 micrograms/ml in the female. The basic biochemical defect appears to be a diminished capacity to oxidize these fatty acids leading to accumulation in cholesterol esters. Fatty acid oxidation to CO2 by cultured skin fibroblasts was 51% of control value for stearic acid, 5% for lignoceric acid in the male, and 39% of control value for stearic acid, 5% for lignoceric acid in the female. The genetics of this disease is different; whereas childhood adrenoleukodystrophy is X-linked, the neonatal onset form affects males and females equally and is most probably autosomally recessive in inheritance.

Familial occurrence of renal and intestinal disease associated with tissue autoantibodies

Chronic tubulointerstitial renal disease and villous atrophy of the small intestine occurred in two first cousins. Both had protracted diarrhea with malabsorption and died despite intensive parenteral alimentation. In one patient signs of generalized proximal tubular dysfunction developed, followed by nephrotic syndrome and progressive renal insufficiency. A renal biopsy specimen disclosed severe tubulointerstitial disease and membranous glomerulopathy. In this patient, circulating immune complexes were detected and granular deposits of IgG and C3 were seen in the intestinal epithelial cells by direct immunofluorescence. Antiintestinal antibodies (IgG class) were demonstrated by indirect immunofluorescence. The other patient had interstitial nephritis but no glomerular abnormality. On direct immunofluorescence, both patients had confluent granular staining of the renal tubular basement membranes. These immunopathologic studies suggest a common immunologic mechanism in the pathogenesis of the renal and gastrointestinal disorders in these infants.

Ductuloinsular tumors of the pancreas: a light, electron microscopic and immunohistochemical study

Most pancreatic tumors are of a single cell type and are identified delta as duct, acinar, or islet cell neoplasms. The authors report on three examples with both duct and endocrine characteristics as seen by light microscopy; two with further confirmation of endocrine differentiation by electron microscopy; and one by immunocytochemistry. Mixed differentiation of this sort can be understood by reference to the embryonic pancreas, which develops from the small intestine and forms ducts, intercalated ducts, acini, and islets, with their different cell types. The merging and intermingling of different cell prevents the identification of one specific cell of origin. It also suggests that the neoplastic process here may not be a clonal proliferation from a single cell mutation as this is generally understood. Alternative explanations are briefly mentioned.

Myocardial aneurysm in association with disseminated cytomegalovirus infection

An infant with disseminated cytomegalovirus infection and apical aneurysm of the left ventricle died. At autopsy the coronary arteries were anatomically normal, but there was occlusion of the left anterior descending artery with an inflammatory lesion and corresponding organized thrombus. It seemed likely that cytomegalovirus infection acquired in utero may have induced an endothelial lesion, leading to thrombosis, occlusion, apical myocardial infarction, and eventual aneurysm formation.

Isolation, characterization and localization of a 45 000 molecular weight, soluble glycoprotein from the lung in pulmonary alveolar proteinosis

A carbohydrate-rich, water-soluble glycoprotein has been isolated in pure form from delipidated lung lavage fluid from a patient with pulmonary alveolar proteinosis, in a three-step procedure involving ion-exchange and gel filtration chromatography. The molecular weight of the glycoprotein was determined to be 45 900 by sedimentation equilibrium analysis in the analytical ultracentrifuge and 45 000 by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, indicating a single polypeptide chain. Nearly half of the mass of the glycoprotein is comprised of carbohydrate that is contributed by 24 residues sialic acid, 23 residues N-acetylglucosamine, 6 residues N-acetylgalactosamine, 19 residues galactose, 4 residues mannose, 1 residue fucose and 1 residue glucose per mol. Unlike a number of collagen-related glycoproteins that have been isolated by others from insoluble lung contents in pulmonary proteinosis, the water-soluble glycoprotein described in the present report does not contain hydroxyproline or hydroxylysine and contains less than 10% of its amino acid residues as glycine. Using rabbit antibodies directed against our purest preparation of material and an immunoperoxidase staining procedure, the 45 000 molecular weight glycoprotein was localized to the thin film of fluid lining the surfaces of alveoli in normal human lungs.

Immunolocalization of entactin, a sulfated basement membrane component, in rodent tissues, and comparison with GP-2 (laminin)

Entactin is a sulfated glycoprotein in the extracellular basement membrane like matrix produced by M1536-B3 cells, a mouse endodermal line derived from an embryonal carcinoma. It has a molecular weight of 158,000 and is chemically and immunologically distinguishable from GP-2 (laminin) and fibronectin. Antibodies produced against entactin and GP-2 react with subepithelial and vascular basement membranes in rat lung, liver, spleen, and kidney and mouse placenta and kidney when examined by light microscopy. Both antibodies yield staining around the marginal sinus of the white pulp of the spleen. Antientactin reacts with basement membrane and mesangium in rat glomeruli, and anti-GP2 does not. Ultrastructurally, staining in kidneys is strongest at epithelial or endothelial cell membranes bordering basement membranes, with only moderate staining of the basement membrane proper. Intracellular staining is not present. The location of entactin suggests that it has a role in the interaction of cells with extracellular matrix, possibly in adhesion. Lack of intracellular staining suggests that the tissues studied are not actively producing entactin or GP-2 and that these substances may be fairly stable in adult organisms.

Entactin, a novel basal lamina-associated sulfated glycoprotein

A sulfated glycoprotein, entactin, of apparent molecular weight 158,000 has been isolated from an extracellular basement membrane-like matrix. This matrix is elaborated in cell culture by a mouse endodermal cell line. Antibodies prepared in rabbits against this sulfated glycoprotein react with mouse and rat basement membranes from a variety of tissues. These antibodies also react in a specific manner with a discrete component of mouse and rat kidney glomeruli. The electrophoretic mobility of this component is identical to that of entactin. The mouse kidney antigen, as shown by immunoelectron microscopic studies, is predominantly localized at the surface of epithelial cells of tubules and glomeruli adjacent to the basement membrane. Some antigen is also present in the basal lamina adjacent to the epithelial cells. Entactin is distinct from the basement membrane-associated protein GP-2, a protein similar to laminin. Entactin differs from GP-2 in electrophoretic mobility, cyanogen bromide peptide fragmentation pattern, immunological cross-reactivity, and incorporation of H235SO4. Entactin is insensitive to treatment with chrondroitinase ABC. It is suggested that this molecule plays a role in the interaction of the extracellular matrix and the cell surface.

Neuroma in the region of the atrioventricular node

A three month old infant died of apparent sudden infant death syndrome. Autopsy showed a neuroma in the region of the atrioventricular node, unassociated with neurofibromatosis. The atrioventricular node and bundle of His were normal. It was not possible to ascribe the sudden death to the neuroma.

Tamm-Horsfall protein in lymph nodes

We found masses of amorphous waxy pale staining material in the peripheral sinuses of lymph nodes removed with renal tumors. The material was histochemically and immunohistochemically identical to Tamm-Horsfall protein. It was found also in tubular casts, renal tubules, and intrarenal lymphatics in the resected kidneys. Tamm-Horsfall protein was restricted to the compressed residual kidney and was not seen in the tumors. Under certain circumstances Tamm-Horsfall protein escapes from the tubules into the renal interstitium and may produce a local inflammatory reaction. It also gains access to intrarenal lymphatics and thence to regional lymph nodes. This may be relevant to the evolution of an antibody response.