Helicobacter pylori infection in intestinal- and diffuse-type gastric adenocarcinomas

Gastric cancer can be divided into two histologic types: intestinal and diffuse. To determine whether Helicobacter pylori, a bacterium linked with gastritis, was associated with either cancer type, we reviewed histologic sections from stomachs of patients who had undergone gastrectomy for gastric cancer. Of 37 of the sections with evidence of intestinal-type cancer, 33 (89.2%) contained H pylori in noncancerous tissue compared with 7 (31.8%) of 22 of the sections with evidence of diffuse-type cancer (odds ratio = 17.7; P less than .001). This association remained strong when controlled for age, sex, site, and number of sections reviewed. The prevalence of H pylori in intestinal-type gastric cancer far exceeded the prevalence of H pylori in diffuse disease and that described in the normal US population. This finding suggests that H pylori may be a cofactor in development of intestinal-type gastric cancer.

Extent of glomerular injury in active and resolving lupus nephritis: a theoretical analysis

Patients with diffuse, proliferative lupus nephritis (DPLN) were subjected to differential solute clearances (n = 22) and serial renal biopsy (n = 11) before and again after 6-12 mo of immunosuppressive therapy. Glomerular sieving of dextrans of graded size was analyzed with a heteroporous membrane model. This revealed active DPLN to be associated with 1) a reduction of overall pore density accompanied by a 53% depression of glomerular filtration rate (GFR), and 2) appearance of a subset of large, nondiscriminatory pores, which accounted for the observed nephrotic level of proteinuria. Morphometric analysis of biopsy tissue provided evidence of reduced filtration surface area due to global or segmental occlusion of capillary loops in glomerular tufts. Activity of DPLN resolved posttreatment. A computed increase in pore density was associated with a 24% increment in GFR; a marked reduction in the fraction of shuntlike pores was accompanied by a parallel reduction of proteinuria into a subnephrotic range. Repeat biopsy revealed diminished glomerular cellularity, fewer immune deposits, and an ensuing increase in the fraction of tuft area occupied by patent loops. Epithelial filtration slit frequency also increased. Neither functional nor structural recovery was complete, however. Residual pore density approximated only 23-35% of that in healthy controls, and corresponding shuntlike pores were threefold more prominent. We conclude that severe DPLN is only partially reversible by current modalities of treatment and that the ensuing residual injury is far more severe than suggested by conventional tests of renal function.

Post-transplantation outcome of patients with hemolytic-uremic syndrome: update

The outcome of renal transplantation in patients with hemolytic-uremic syndrome (HUS) is variable in reported cases. An update of the previously published series of patients from the University of Minnesota is reported. Seventeen patients with HUS received a renal transplant. Seven patients had recurrent HUS based on strict clinical and histological features and in 4 of these patients grafts were loss from recurrent HUS, with 1 patient losing three successive grafts. Three patients had histological features consistent with HUS but lacked some of the clinical features. Seven patients had no evidence of recurrent HUS post transplantation. The incidence of recurrence of HUS post transplantation in this updated report remains high (7/17 patients). There was no difference in the allografts used (living-related donor grafts were more common in all groups) or in the immunosuppression in the different groups of patients; only 1 patient with recurrent HUS received cyclosporine. The published cases of transplantation in patients with HUS show a variable recurrence rate of 0-25% in different centers with a poor graft outcome in patients with recurrence; a higher incidence of early chronic vascular rejection with decreased graft survival is also reported in patients without recurrence. Patients with HUS post renal transplant are at a variable risk of recurrence of HUS or decreased graft survival, and the factors responsible for this outcome are not known.

Acute lung rejection after heart-lung transplantation: correlation of findings on chest radiographs with lung biopsy results

This retrospective study was performed to determine if the chest radiograph could serve as a predictor for acute lung rejection in heart-lung transplantation patients. The findings on chest radiographs were correlated with the results of transbronchial biopsies in 16 heart-lung transplantation patients. The chest radiographs immediately preceding 83 biopsies were evaluated for a variety of findings. The histopathologic results of the lung biopsies were divided into five categories: (1) acute lung rejection (n = 25); (2) suggestive, but not diagnostic, of acute lung rejection (n = 8); (3) nonspecific (n = 26); (4) infection (n = 17); and (5) normal lung (n = 9). Biopsies from two patients showed both acute lung rejection and cytomegalovirus infection and were included in both categories. These histopathologic results were then correlated with the radiologic observations. We found that the combination of septal lines and new or increasing pleural effusions, without concomitant increase in cardiac size or vascular pedicle width, or evidence of vascular redistribution, indicated acute lung rejection with a sensitivity of 68% (17/25), specificity of 90% (52/58), and overall accuracy of 83% (69/83). We conclude that the chest radiograph is a useful indicator of acute lung rejection.

Manifestations of renal allograft rejection in small children receiving adult kidneys

We were concerned that clinical manifestations of rejection (R) might be subtle in small children transplanted with adult kidneys. We retrospectively analyzed the first rejection episode (biopsy proven) in 22 children (R group) under age 4 years [mean age, 23.7 +/- 2.2 months (+/- SEM); mean weight, 9.4 +/- 0.4 kg] receiving an adult-related donor kidney. We matched these patients for age, date of transplant, donor source and immunosuppression with 36 children without R (control or C group). We compared both groups at similar intervals from transplantation, based on the time of R (5.38 +/- 1.2 months) in the R group and analyzed the immediate 8-week period prior to R and the corresponding interval in the C group. Hypertension occurred in 82% (18/22) of the R versus 8% (3/36) of the C group (P less than 0.01). Fever longer than 7 days occurred in 45% (10/22) of the R versus 0% (0/36) of the C group (P less than 0.01). Increased creatinine occurred in only 45% (10/22) of the R versus 3% (1/30) of the C group (P less than 0.01). Cyclosporine did not influence these manifestations of R. The clinical manifestations did not predict the R grades on biopsy, which were moderate to severe in 13 and mild in 9 of the R patients. Graft survival was higher at 3 years in the C (95%) than in the R patients (65%), (P less than 0.004). Thus, clinical manifestations of acute R can be subtle in small children with adult renal allografts. Renal biopsy should not be delayed until the creatinine is elevated in these patients.

Doppler evaluation of renal transplants in children: a prospective analysis with histopathologic correlation

Duplex Doppler sonography recently has been used to evaluate renal transplants. Some authors have stated that high resistive indexes (RIs) occur in the presence of acute renal transplant rejection. RIs less than 0.7 are considered as probably excluding acute transplant rejection. We performed a prospective study of duplex sonographic examinations of pediatric patients (mean age, 8 years; 13 boys, two girls) with renal allografts and clinically suspected transplant disease. The results of 22 duplex studies were correlated with histopathologic data obtained between July 1987 and June 1988. RIs of the arcuate arteries in patients with acute rejection (n = 14) averaged 0.62 (range, 0.50-0.80). The RI in patients with chronic rejection (n = 1) was 0.59. RIs in patients with acute tubular necrosis (n = 3) averaged 0.66 (range, 0.59-0.72). RIs in patients with cyclosporine A toxicity (n = 4) averaged 0.66 (range, 0.58-0.79). Tubulointerstitial rejection was predominant, with only two patients showing minimal acute vascular rejection. Thirteen of 14 pediatric patients with histologically proved renal transplant rejection had a resistive index of less than 0.70. This study refutes the concept that resistive indexes of less than 0.7 exclude acute rejection.

Evaluation of heart-lung transplant recipients with prospective, serial transbronchial biopsies and pulmonary function studies

The insidious development of obliterative bronchiolitis after heart-lung transplantation is thought to be due to rejection and possibly infection (cytomegalovirus). To evaluate further, we prospectively managed the last 16 consecutive heart-lung transplant recipients with serial transbronchial biopsies with lavage and pulmonary function studies as part of a surveillance protocol or as dictated by clinical presentation. A total of 123 transbronchial biopsies with lavage were performed, 77 for clinical indications (group I) and 46 for routine surveillance (group II). Results of 64 (83.1%) group I biopsies were positive for rejection or infection. Thirty-one of these biopsy specimens showed signs of rejection (29 in group I and two in group II), characterized by a perivascular mononuclear infiltrate, lymphocytic bronchiolitis, and occasionally alveolar septal mononuclear infiltrate. Forty-six serial pulmonary function tests were performed. The forced expiratory volume in 1 second (percent predicted), forced expiratory flow rate between 25% and 75% of the forced vital capacity (percent predicted), and arterial oxygen tension (millimeters of mercury) were significantly reduced from baseline values during rejection episodes: forced expiratory volume in 1 second, 75.7% +/- 20.1% versus 52.7% +/- 18.3% (p less than or equal to 0.05); forced expiratory flow rate between 25% and 75% of the forced vital capacity, 97.6% +/- 30.5% versus 49.8% +/- 22.3% (p less than or equal to 0.05); and arterial oxygen tension, 92.1 +/- 8.8 mm Hg versus 71.4 +/- 18.8 mm Hg (p less than or equal to 0.05). The fall in pulmonary function was reversible with pulse methylprednisolone. Asynchronous heart and lung rejection was documented. Of the 29 episodes of pulmonary rejection, 18 (62%) occurred asynchronously. Ten of the 16 (62%) heart-lung recipients had at least one episode of cardiac rejection. Thirteen of 16 (81%) had at least one episode of lung rejection. Serial transbronchial biopsies with lavage, as dictated by pulmonary function tests and clinical status, have guided early and more specific therapy directed against rejection and infection. With early detection, small airway dysfunction has been reversible.

Pulmonary infiltrates after heart-lung transplantation: evaluation by serial transbronchial biopsies

Since January 1988, prospective serial transbronchial lung biopsies have been performed as a diagnostic procedure to facilitate the care of recipients of heart-lung transplants. Eighty-five cardiac and 70 transbronchial lung biopsies have been prospectively performed in 10 patients beginning within the first week of transplantation. Forty-eight percent (34/70) of the transbronchial lung biopsies and 16.5% (14/85) of the heart biopsies were positive for either rejection or infection. Pulmonary rejection was evident by a perivascular lymphocytic infiltrate that cleared with pulse steroid therapy. Pulmonary and cardiac rejection were present synchronously on six occasions and asynchronously on 16 occasions (nine pulmonary and seven cardiac). Four patients had early cytomegalovirus pneumonitis on biopsy specimen and were successfully treated with ganciclovir. Of the 40 clinically indicated biopsies, 29 (72.5%) were positive for rejection or infection and guided subsequent therapy. In summary, transbronchial lung biopsies have provided prompt (within 24 hours) serial diagnostic information that has guided successful treatment of infection (cytomegalovirus, aspergillosis, and Pneumocystis) and rejection. Asynchronous rejection of the heart and lungs has been conclusively demonstrated. With the early detection of rejection and infection, we are optimistic that chronic airway disease in patients with a heart-lung transplant may be reduced.

Outcome of the acute glomerular injury in proliferative lupus nephritis

Treatment with total lymphoid irradiation (TLI) and corticosteroids markedly reduced activity of systemic lupus erythematosis in 10 patients with diffuse proliferative lupus nephritis (DPLN) complicated by a nephrotic syndrome. Physiologic and morphometric techniques were used serially before, and 12 and 36 mo post-TLI to characterize the course of glomerular injury. Judged by a progressive reduction in the density of glomerular cells and immune deposits, glomerular inflammation subsided. A sustained reduction in the fractional clearance of albumin, IgG and uncharged dextrans of radius greater than 50 A, pointed to a parallel improvement in glomerular barrier size-selectivity. Corresponding changes in GFR were modest, however. A trend towards higher GFR at 12 mo was associated with a marked increase in the fraction of glomerular tuft area occupied by patent capillary loops as inflammatory changes receded. A late trend toward declining GFR beyond 12 mo was associated with progressive glomerulosclerosis, which affected 57% of all glomeruli globally by 36 mo post-TLI. Judged by a parallel increase in volume by 59%, remaining, patent glomeruli had undergone a process of adaptive enlargement. We propose that an increasing fraction of glomeruli continues to undergo progressive sclerosis after DPLN has become quiescent, and that the prevailing GFR depends on the extent to which hypertrophied remnant glomeruli can compensate for the ensuing loss of filtration surface area.

Immunohistochemical localization of laminin in the basement membranes of normal, hyperplastic, and neoplastic human prostate

We examined the effects of fixatives and antibody sources on the immunohistologic localization of laminin in normal and cancer-containing human prostates and studied the localization patterns in carcinomas of varying degrees of histologic differentiation. Two different polyclonal antibodies were localized in paraffin-embedded or cryostat sections of fixed (alcohol, formalin, and paraformaldehyde) or unfixed tissue, using the immunofluorescence (IF) or immunoperoxidase (IP) techniques, with positive and negative controls. We found that the IF reactions were more intense in unfixed or alcohol-fixed sections than in paraformaldehyde-fixed specimens. IP reactions were very weak or absent in fixed and paraffin-embedded sections, but pepsin treatment of these sections resulted in more intense and uniform IP reaction products, stronger than in unfixed or ethanol-fixed cryostat sections. With the IP technique, laminin localization was intense and uniform in the basement membranes (BM) of acini, blood vessels, smooth muscle, and nerve fibers in normal prostate, benign hyperplasia (BPH), and well-differentiated carcinomas. The BM of poorly differentiated carcinomas showed widespread absence of laminin reactivity. In normal BPH and well-differentiated tumors, occasional epithelial cells and their surface and acinar lumina had laminin reactivity. However, in higher grade tumors, numerous neoplastic cells had laminin reactivity in cytoplasm, their surface, and secretory material. Some macrophages and neutrophils also contained laminin reactivity, presumably of degraded laminin. In some moderately and poorly differentiated tumors, the BM of small capillaries did not contain laminin. The BM of larger vessels always had laminin reactivity, even in the higher grade tumors.

Recurrence of disease in pancreas transplants

In a series of 200 pancreas transplants with 6 mo to less than 9 yr of follow-up, recurrence of disease was identified as the cause of graft failure in 8 cases, all in non- or minimally immunosuppressed recipients of transplants from identical twin (n = 3) or HLA-identical sibling (n = 5) donors. Recurrence of disease was defined as selective loss of beta-cells; other endocrine cell types persisted and appeared normal within the islets of the graft. Isletitis was present in islets with residual beta-cells during the evolution of the process in all nonimmunosuppressed and in some immunosuppressed recipients, but isletitis resolved in all cases in which beta-cell destruction was complete and also resolved in some cases in which residual beta-cells were retained after the introduction of or an increase in immunosuppression. Recurrence of disease can be prevented by immunosuppression, and 2 recipients of identical twin grafts and 12 recipients of grafts from HLA-identical siblings had functioning grafts as of March 1988, the longest greater than 7 yr. The process has not been observed in patients in whom full-dose immunosuppression has been used, including HLA-identical siblings, and this may be the reason no cases of recurrence of disease have been identified in recipients of cadaveric grafts. Alternatively, the observations are consistent with, but not proof of, the hypothesis that recurrence of disease (autoimmune isletitis leading to diabetes) is a major histocompatibility complex-restricted phenomenon.

Chronic injury of human renal microvessels with low-dose cyclosporine therapy

Physiologic and morphologic techniques were used to study kidneys of cardiac transplant recipients treated with either low-dose (low-CsA) or high-dose (high-CsA) cyclosporine. After 12 months both low-CsA (4.6 +/- 0.4) and high-CsA (6.3 +/- 0.3 mg/Kg/24 hr, p less than 0.01) were associated with azotemia and hypertension; GFR with each regimen was depressed below values in a third group treated without CsA (no-CsA) by 40-47%, while corresponding renal vascular resistance was elevated greater than 2-fold (P less than 0.01). Morphologic changes in both CsA groups included an obliterative arteriolopathy with downstream collapse or sclerosis of glomeruli. Determination of renal arcuate vein occlusion pressure revealed an increasing renal artery-to-peritubular capillary pressure gradient between 1 and 12 months of CsA therapy. Fractional clearances of dextrans of graded size were elevated at each time compared with the no-CsA group. Analysis of dextran transport with an isoporous membrane model indicates that transglomerular hydraulic pressure difference (delta P) approximated 39 with no-CsA, but was reduced with low-CsA therapy to about 30 at 1 month, and about 34 mmHg after 12 months. We conclude that chronic CsA therapy induces constriction and eventual occlusion of afferent arterioles, causing downstream glomerular damage that is irreversible. Low versus high dosage of CsA confers only marginal protection against this serious microvascular injury.

Anaphylactoid purpura: characteristics of 16 patients who progressed to renal failure

Renal insufficiency occurs in at least 1.5% of children with anaphylactoid purpura (AP). We reviewed the records of 16 children who developed end-stage renal disease (ESRD group) secondary to AP and matched them for age, era of onset, renal histology, and clinical severity at onset with 16 children who had AP but whose creatine clearance returned to and remained normal (recovery group). We reviewed creatinine clearances at 1, 3, 5, and 10 years after onset. A creatinine clearance greater than 70 ml/min per 1.73 m2 was present in 50% of the patients in the ESRD group at 3 years and in 25% at 5 years after onset. In contrast, all patients in the recovery group had a creatinine clearance greater than 70 ml/min per 1.73 m2 by 3 years (7 of 16 had a creatinine clearance greater than 125 ml/min per 1.73 m2) and all were normal 95-125 ml/min per 1.73 m2) by 5 years. Thus, the presence of an increased creatinine clearance (greater than 125 ml/min per 1.73 m2) at 3 years predicted recovery, while failure to reach a creatinine clearance of greater than 70 ml/min per 1.73 m2 at 3 years predicted progression to ESRD. There was no evidence of recurrent systemic AP or nephritis in the 14 patients who underwent renal allograft transplantation. We conclude that long-term evaluation of patients over many years is required to identify those who will progress to ESRD from AP and that recurrence of AP in the renal transplant is uncommon.

Comparison of cyclosporin A and G with and without azathioprine regarding immunosuppressive efficacy, toxicity, and pharmacokinetics in Lewis rats

Cyclosporin A-associated nephrotoxicity has precipitated the need to develop new immunosuppressive protocols or agents that have a higher therapeutic index than cyclosporin A. A new immunosuppressive agent, cyclosporin G or norvaline (Nva-2) cyclosporine, has been shown to be potent. The rat heterotopic transplant model (ACI to Lewis) and Lewis rats that had no operation were used to compare cyclosporin G with cyclosporin A (5 mg/kg/day per gavage) with and without azathioprine (5 to 10 mg/kg/day, intraperitoneally) in terms of immunosuppressive efficacy (graft survival), toxicity (mortality, renal histopathology, and serum creatinine and blood urea nitrogen values), and pharmacokinetics (trough whole blood cyclosporine levels as measured by radioimmunoassay on days 14 and 28 of treatment). In this model no statistically significant difference in immunosuppression was shown between the two cyclosporins both with and without azathioprine. Cyclosporin G, however, was associated with significantly less mortality when combination therapy with azathioprine was used. Both cyclosporins were associated with normal serum creatinine values and little histopathologic evidence of nephrotoxicity, except juxtaglomerular apparatus hyperplasia. Comparable cyclosporine levels were achieved when cyclosporin A or G was used as the sole immunosuppressive agent, but significantly higher cyclosporine levels were shown with cyclosporin A than with cyclosporin G when combination therapy with azathioprine was used. Further studies in humans are needed to evaluate whether cyclosporin G will be a clinically useful immunosuppressive agent either alone or combined with other immunosuppressive modalities.

Primary cerebral neuroectodermal tumors: neuroblastoma, differentiated neuroblastoma, and composite neuroectodermal tumor

Seven cases of primary cerebral neuroectodermal tumors with predominant neuroblastic features were studied ultrastructurally and five were evaluated immunohistochemically. The fine structural features were indicative of neuroblastic differentiation by the presence of elongated cytoplasmic processes, electron-dense neurosecretory granules, and neurotubules. Five of the seven cases had the morphologic findings of classic cerebral neuroblastoma, and the sixth case, originally diagnosed as an oligodendroglioma, had the features of a differentiated neuroblastoma. Desmoplastic and/or stromal foci were intermingled with neuronal-ganglionic cells and neuroblasts in the seventh case. In addition to strong immunoreactivity for S-100 protein and glial fibrillary acidic protein in the desmoplastic areas, the spindle cells had fibroblastic and Schwannian features by electron microscopy in the latter case. The neuroblastic cells and fibrillary network were immunoreactive for neuron-specific enolase and neurofilament in the five study cases. It is concluded that cerebral neuroectodermal tumors may express an range of phenotypic features from the exclusive neuroblastic stage to a neuronal and stromogenic phase analogous to the classic neuroblastoma of the sympathetic nervous system.

The mitochondrial respiratory toxicity of cephalosporin antibiotics. An inhibitory effect on substrate uptake

Cephalosporin antibiotics can produce renal cortical mitochondrial respiratory toxicity after either in vitro or in vivo exposure. In vitro toxicity is immediate, nonselective among toxic and nontoxic cephalosporins and reversed by substrate excess. In vivo toxicity is delayed, specific to the nephrotoxic cephalosporins and not reversible. Both routes of exposure affect respiration with succinate (S) more than with glutamate plus malate as substrates. Because glutamate and malate gain access to the intramitochondrial electron transport chain proximal to S, this pattern suggests that the cephalosporins affect a mitochondrial function outside the respiratory chain. A model of respiratory toxicity incorporating all of these features proposes that all cephalosporins can fit the affected transporters for mitochondrial substrate uptake, but, in the intact kidney, this causes limited or transient respiratory inhibition with nontoxic cephalosporins; in vivo toxicity, which is seen after later isolation and washing of mitochondria exposed in situ, develops with the more sequestered and reactive (nephrotoxic) cephalosporins that acylate these transporters. As a test of this hypothesis, studies were done, using the method of sieve filtration, to evaluate the effects of in vivo and in vitro exposure to cephaloglycin (toxic) and cephalexin (nontoxic) on the uptake of S and ADP by rabbit renal cortical mitochondria. In vivo and in vitro exposure to cephaloglycin reduced the net uptake of S by 70% and had a considerably smaller and less consistent effect on ADP uptake; cephalexin inhibited S uptake only with in vitro exposure. The rate of S washout from cephaloglycin-intoxicated mitochondria was no greater than from controls, ruling out increased efflux as a cause of decreased net uptake.(ABSTRACT TRUNCATED AT 250 WORDS)

The long-term course of cyclosporine-associated chronic nephropathy

We evaluated a chronic renal injury in 37 cardiac transplant recipients treated for 12 to 24 months with cyclosporine (CsA). Twenty-four cardiac transplant recipients treated with azathioprine for more than 24 months served as controls. Despite equivalent cardiac performance, GFR in those treated with CsA was depressed, 47 +/- 3 versus 94 +/- 4 ml/min/1.73 m2 (P less than 0.001). CsA therapy was also associated with significant elevation of renal vascular resistance (RVR), proteinuria, arterial hypertension, and impaired intrarenal conversion of inactive prorenin to active renin. Histopathological changes associated with CsA included an obliterative arteriolopathy with deposition of proteinaceous material in necrotic arteriolar walls, and associated tubulointerstitial damage. A minority of glomeruli exhibited either ischemic collapse or sclerosis. Area perimeter analysis revealed enlargement of the remaining glomeruli with significant expansion of the mesangium. Longitudinal examination over a 48 month period (N = 15) during which CsA was reduced in dosage or withdrawn revealed persistent hypofiltration, increasingly elevated RVR and heavier proteinuria. Further histopathological deterioration was observed when renal tissue was sampled a second time in six patients, and three members of the experimental group developed end-stage renal disease. We conclude that continuous CsA therapy for more than 12 months causes a chronic injury to renal microvessels that is rarely reversible and potentially progressive.

Resolution of obstructive sleep apnea in Hurler syndrome after bone marrow transplantation

Hurler syndrome, a lethal inborn error of lysosomal metabolism, results from the systemic accumulation of glycosaminoglycan. The progressive deposition of glycosaminoglycan in tissues of the upper aerodigestive tract has been suspected as the cause of airway obstruction, and many children have required tracheostomy. In a 3-year-old patient with Hurler syndrome, polysomnography confirmed the clinical impression of obstructive sleep apnea. Biopsy of an enlarged tonsil demonstrated that more than half the tissue volume resulted from abnormal lysosomal inclusions in macrophages. Three months after transplantation, repeat testing demonstrated resolution of airway obstruction, and 6 months after transplantation, tonsil biopsy showed complete absence of lysosomal inclusions. Bone marrow transplantation produces effective metabolic correction for Hurler syndrome and may be life-saving for patients with obstructive apnea.

Pancreas transplantation. An immunohistologic and histopathologic examination of 100 grafts

The authors examined tissues obtained by biopsy, pancreatectomy, and autopsy from 100 pancreas grafts to determine the cause of dysfunction or failure of the graft. Immunohistologic examination of 42 tissues to determine the mononuclear cell phenotypes and Class I and II antigen expression was performed as well. Technical factors--infections, thrombosis, obstruction--accounted for a large number of graft losses, but immunologic-mediated mechanisms resulted in graft dysfunction and failure as well. Pleomorphic inflammatory infiltrates were present in grafts with acute rejection, as well as Silastic and Prolamine duct-obstructed grafts. Criteria useful in the identification of acute rejection from pancreatitis included a more intense, predominantly mononuclear cell infiltration of transformed lymphocytes in the exocrine pancreas and evidence of vascular rejection--endovasculitis or fibrinoid necrosis. Increased expression and/or induction of Class I and II antigens on pancreatic constituents occurred in grafts with evidence of acute rejection, but also with Silastic and prolamine duct-obstructed pancreatitis. An isletitis occurred in 25% of the grafts. Nine of the 25 grafts (36%) with isletitis also had selective loss of beta cells from the islets. Recurrent diabetes mellitus appeared to have developed in these cases, which accounted for loss of graft function.

Carcinoid tumors of the middle ear

Carcinoid tumors of the middle ear are rare, with only three previously reported cases. The authors report the light and electron microscopic and immunohistochemical features of two carcinoid tumors that occurred in a 34-year-old female and a 21-year-old male. Both presented with unilateral hearing loss. By light microscopic examination, both were characterized by trabecula of tall columnar cells with basal nuclei and no mitotic activity. Electron microscopic examination demonstrated large numbers of pleomorphic neurosecretory granules, perinuclear aggregates of intermediate filaments, cell junctions, and surface microvillous processes. Some cells contained intermediate filaments forming tonofilaments and lacked secretory granules. These cells stained for cytokeratin by immunoperoxidase and separated the neuroendocrine cells from the underlying basal lamina. The cells in this tumor stained for the molluscan cardioexcitatory peptide. Cells in both tumors also stained for pancreatic polypeptide. Neither case stained for lysozyme, insulin, glucagon, somatastatin, gastrin, substance P, thyroid-stimulating hormone, adrenocorticotropic hormone, Met-enkephalin, Leu-enkephalin, neuropeptide Y, peptide YY, neurotensin, Bombesin, serotonin, neuron-specific enolose, glial and neural filaments, S-100 protein, cholecystokinin, beta-endorphin, beta-human chorionic gonadotropin, luteinizing hormone/follicle-stimulating hormone, vasoactive intestinal polypeptide, prolactin or calcitonin. Carcinoid tumor of the middle ear can be distinguished from paraganglioma and middle ear adenoma.