Liquid plug propagation in computer-controlled microfluidic airway-on-a-chip with semi-circular microchannels

This paper introduces a two-inlet, one-outlet lung-on-a-chip device with semi-circular cross-section microchannels and computer-controlled fluidic switching that enables a broader systematic investigation of liquid plug dynamics in a manner relevant to the distal airways. A leak-proof bonding protocol for micro-milled devices facilitates channel bonding and culture of confluent primary small airway epithelial cells. Production of liquid plugs with computer-controlled inlet channel valving and just one outlet allows more stable long-term plug generation and propagation compared to previous designs. The system also captures both plug speed and length as well as pressure drop concurrently. In one demonstration, the system reproducibly generates surfactant-containing liquid plugs, a challenging process due to lower surface tension that makes the plug formation less stable. The addition of surfactant decreases the pressure required to initiate plug propagation, a potentially significant effect in diseases where surfactant in the airways is absent or dysfunctional. Next, the device recapitulates the effect of increasing fluid viscosity, a challenging analysis due to higher resistance of viscous fluids that makes plug formation and propagation more difficult particularly in airway-relevant length scales. Experimental results show that increased fluid viscosity decreases plug propagation speed for a given air flow rate. These findings are supplemented by computational modeling of viscous plug propagation that demonstrates increased plug propagation time, increased maximum wall shear stress, and greater pressure differentials in more viscous conditions of plug propagation. These results match physiology as mucus viscosity is increased in various obstructive lung diseases where it is known that respiratory mechanics can be compromised due to mucus plugging of the distal airways. Finally, experiments evaluate the effect of channel geometry on primary human small airway epithelial cell injury in this lung-on-a-chip. There is more injury in the middle of the channel relative to the edges highlighting the role of channel shape, a physiologically relevant parameter as airway cross-sectional geometry can also be non-circular. In sum, this paper describes a system that pushes the device limits with regards to the types of liquid plugs that can be stably generated for studies of distal airway fluid mechanical injury.

Liquid plug propagation in computer-controlled microfluidic airway-on-a-chip with semi-circular microchannels

This paper introduces a two-inlet, one-outlet lung-on-a-chip device with semi-circular cross-section microchannels and computer-controlled fluidic switching that enables a broader systematic investigation of liquid plug dynamics in a manner relevant to the distal airways. A leak-proof bonding protocol for micro-milled devices facilitates channel bonding and culture of confluent primary small airway epithelial cells. Production of liquid plugs with computer-controlled inlet channel valving and just one outlet allows more stable long-term plug generation and propagation compared to previous designs. The system also captures both plug speed and length as well as pressure drop concurrently. In one demonstration, the system reproducibly generates surfactant-containing liquid plugs, a challenging process due to lower surface tension that makes the plug formation less stable. The addition of surfactant decreases the pressure required to initiate plug propagation, a potentially significant effect in diseases where surfactant in the airways is absent or dysfunctional. Next, the device recapitulates the effect of increasing fluid viscosity, a challenging analysis due to higher resistance of viscous fluids that makes plug formation and propagation more difficult particularly in airway-relevant length scales. Experimental results show that increased fluid viscosity decreases plug propagation speed for a given air flow rate. These findings are supplemented by computational modeling of viscous plug propagation that demonstrate increased plug propagation time, increased maximum wall shear stress, and greater pressure differentials in more viscous conditions of plug propagation. These results match physiology as mucus viscosity is increased in various obstructive lung diseases where it is known that respiratory mechanics can be compromised due to mucus plugging of the distal airways. Finally, experiments evaluate the effect of channel geometry on primary human small airway epithelial cell injury in this lung-on-a-chip. There is more injury in the middle of the channel relative to the edges highlighting the role of channel shape, a physiologically relevant parameter as airway cross-sectional geometry can also be non-circular. In sum, this paper describes a system that pushes the device limits with regards to the types of liquid plugs that can be stably generated for studies of distal airway fluid mechanical injury.

The origin of blinking in both mudskippers and tetrapods is linked to life on land

Blinking, the transient occlusion of the eye by one or more membranes, serves several functions including wetting, protecting, and cleaning the eye. This behavior is seen in nearly all living tetrapods and absent in other extant sarcopterygian lineages suggesting that it might have arisen during the water-to-land transition. Unfortunately, our understanding of the origin of blinking has been limited by a lack of known anatomical correlates of the behavior in the fossil record and a paucity of comparative functional studies. To understand how and why blinking originates, we leverage mudskippers (Oxudercinae), a clade of amphibious fishes that have convergently evolved blinking. Using microcomputed tomography and histology, we analyzed two mudskipper species, Periophthalmus barbarus and Periophthalmodon septemradiatus, and compared them to the fully aquatic round goby, Neogobius melanostomus. Study of gross anatomy and epithelial microstructure shows that mudskippers have not evolved novel musculature or glands to blink. Behavioral analyses show the blinks of mudskippers are functionally convergent with those of tetrapods: P. barbarus blinks more often under high-evaporation conditions to wet the eye, a blink reflex protects the eye from physical insult, and a single blink can fully clean the cornea of particulates. Thus, eye retraction in concert with a passive occlusal membrane can achieve functions associated with life on land. Osteological correlates of eye retraction are present in the earliest limbed vertebrates, suggesting blinking capability. In both mudskippers and tetrapods, therefore, the origin of this multifunctional innovation is likely explained by selection for increasingly terrestrial lifestyles.

A High-Throughput Distal Lung Air-Blood Barrier Model Enabled By Density-Driven Underside Epithelium Seeding

High-throughput tissue barrier models can yield critical insights on how barrier function responds to therapeutics, pathogens, and toxins. However, such models often emphasize multiplexing capability at the expense of physiologic relevance. Particularly, the distal lung's air-blood barrier is typically modeled with epithelial cell monoculture, neglecting the substantial contribution of endothelial cell feedback in the coordination of barrier function. An obstacle to establishing high-throughput coculture models relevant to the epithelium/endothelium interface is the requirement for underside cell seeding, which is difficult to miniaturize and automate. Therefore, this paper describes a scalable, low-cost seeding method that eliminates inversion by optimizing medium density to float cells so they attach under the membrane. This method generates a 96-well model of the distal lung epithelium-endothelium barrier with serum-free, glucocorticoid-free air-liquid differentiation. The polarized epithelial-endothelial coculture exhibits mature barrier function, appropriate intercellular junction staining, and epithelial-to-endothelial transmission of inflammatory stimuli such as polyinosine:polycytidylic acid (poly(I:C)). Further, exposure to influenza A virus PR8 and human beta-coronavirus OC43 initiates a dose-dependent inflammatory response that propagates from the epithelium to endothelium. While this model focuses on the air-blood barrier, the underside seeding method is generalizable to various coculture tissue models for scalable, physiologic screening.

Randomized Controlled Trial Comparing the Effects of Far-Infrared Emitting Ceramic Fabric Shirts and Control Polyester Shirts on Transcutaneous PO2

Our aim was to confirm earlier studies showing tcPO₂ to be higher under clothing made with polyethylene terephalate (PET) fabric containing ceramic particles (CEL) compared to standard PET fabric. In previous studies PET garments were donned first to avoid possible persistent effects from ceramic particles. This study randomized donning sequence to avoid bias.

Race-ethnicity and poverty after spinal cord injury

Objective

Our objective was to examine the relationship between race-ethnicity and poverty status after spinal cord injury (SCI).

Study Design

Secondary analysis of existing data.

Setting

A large specialty hospital in the southeastern United States (US).

Methods

Participants were 2,043 adults with traumatic SCI in the US. Poverty status was measured using criteria from the US Census Bureau.

Results

Whereas only 14% of non-Hispanic White participants were below the poverty level, 41.3% of non-Hispanic Blacks were in poverty. Logistic regression with three different models identified several significant predictors of poverty including marital status, years of education, level of education, age, and employment status. Non-Hispanic Blacks had 2.75 greater odds of living in poverty after controlling for other factors, including education and employment.

Conclusions

We may need to consider quality of education and employment to better understand the elevated risk of poverty among non-Hispanic Blacks in the US.

Construct validity of the FOCUS© (Focus on the Outcomes of Communication Under Six): a communicative participation outcome measure for preschool children

OBJECTIVE

The aim of this study was to establish the construct validity of the Focus on the Outcomes of Communication Under Six (FOCUS©). This measure is reflective of concepts in the International Classification of Functioning Disability and Health--Children and Youth framework. It was developed to capture 'real-world' changes (e.g. communicative participation) in preschoolers' communication following speech-language intervention.

METHOD

A pre-post design was used. Fifty-two parents of 3- to 6-year-old preschoolers attending speech-language therapy were included as participants. Speech-language therapists provided individual and/or group intervention to preschoolers. Intervention targeted: articulation/phonology, voice/resonance, expressive/receptive language, play, and use of augmentative devices. Construct validity for communicative participation was assessed using pre-intervention and post-intervention parent interviews using the FOCUS© and the communication and socialization domains of the Vineland Adaptive Behavior Scales-II (VABS-II).

RESULTS

Significant associations were found between the FOCUS©, measuring communicative participation, and the VABS-II domains for: (i) pre-intervention scores in communication (r = 0.53, P < 0.001; 95% CI 0.30-0.70) and socialization (r = 0.67, P < 0.001; 95% CI 0.48-0.80); (ii) change scores over-time in communication (r = 0.45, P < 0.001; 95% CI 0.201-0.65) and socialization (r = 0.39, P = 0.002; 95% CI 0.13-0.60); and (iii) scores at post-intervention for communication (r = 0.53, P < 0.001; 95% CI 0.30-0.70) and for socialization (r = 0.37, P = 0.003; 95% CI 0.11-0.50).

CONCLUSIONS

The study provided evidence on construct validity of the FOCUS© for evaluating real-world changes in communication. We believe that the FOCUS© is a useful measure of communicative participation.

Measuring communicative participation using the FOCUS©: Focus on the Outcomes of Communication Under Six

BACKGROUND

The FOCUS© is a new outcome tool for use by both parents and clinicians that measures changes in the communicative participation skills of preschool children. Changes in communicative participation skills as measured by the FOCUS were compared across three groups of children: those with speech impairments only (SI), those with language impairments only (LI) and those with both speech and language impairments (S/LI).

METHODS

Participating families (n = 112, 75 male children) were recruited through 13 Canadian organizations. Children ranged from 10 months to 6 years 0 months (mean = 2.11 years; SD = 1.18 years) and attended speech-language intervention. Parents completed the FOCUS at the start and end of treatment. There were 23 children in the SI group, 62 children in the LI group and 27 children in the S/LI group. The average amount of the children's therapy varied from 7 to 10 h.

RESULTS

The FOCUS captures changes in communicative participation for children with a range of communication disorder types and severities. All three groups of children made clinically important improvements according to their FOCUS scores (MCID ≥ 16 points). The FOCUS captured improvements in intelligibility, independent communication, play and socialization.

CONCLUSIONS

The FOCUS measured positive changes in communicative participation skills for all three groups of children after 7-10 h of speech-language therapy. An outcome measure that targets only specific speech and language skills would miss many of the important social function changes associated with speech-language treatment.

The role of Notch3 signaling pathway in pancreatic cancer

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Background: Given the extremely poor prognosis of patients diagnosed with pancreatic cancer, identifying new targets for therapeutic intervention is crucial in improving clinical outcome. Existing data support a role for Notch3 pathway in human cancer, pancreas cancer in specific and in normal pancreas development. Method: We developed a pancreatic tissue array. An antibody targeting the extracellular domain of Notch3 was used to evaluate expression levels, grading from 0 to 4+ to determine the prevalence of Notch3 in pancreatic cancer. Notch3 expression was used to correlate with clinical data (IRB approved). Using small interfering RNA (siRNA) we tested the downstream effects of Notch3 in pancreatic cancer cell line BxP3 in vitro. Furthermore, to study pharmacologic inhibition of Notch3 processing and activation we exposed Panc-1, HPAF II and BxP3 pancreas cancer cell lines to γ-secretase inhibitors (previously demonstrated to block upstream of Notch3 thereby inhibiting Notch3). Results: Strong staining (+2 or greater) for Notch3 was seen in 50 of 72 (69%) resected specimens. No correlation with survival or tumor grade was seen. Using siRNA, we demonstrated that inhibiting Notch3 downregulated the antiapoptotic protein Bcl-xL but not Bcl-2. When γ-secretase inhibitors (GSI and L-685,458) were used, the previously mentioned pancreatic cell lines demonstrated reduction in proliferation rates. Conclusion: Notch3 overexpression is common in pancreas cancer. While Notch 3 expression does not clearly correlate with survival, our in vitro data suggest that Notch3 affects apoptotic pathways and may represent a potential target for intervention in patients with pancreatic cancer.

No significant financial relationships to disclose.

Supra-elevated CA 19-9 in a benign hepatic cyst adenoma

BACKGROUND

Elevated CA 19-9 may be found in both cystadenomas and cystadenocarcinomas of the liver.

CASE OUTLINE

A 59-year-old woman presented with right upper quadrant abdominal pain, malaise and weight loss. Physical examination and laboratory evaluation revealed a mass in the right upper quadrant and a CA 19-9 level of 68 661 U/ml. CT scan demonstrated a cystic liver mass. She underwent a right hepatectomy, and her CA 19-9 returned to normal. Pathologic analysis revealed no malignancy.

DISCUSSION

In hepatic cystic neoplasms, an elevated CA 19-9 should not be used to establish the diagnosis of malignancy nor should it preclude resection.

Dysplasia as a predictive marker for invasive carcinoma in Barrett esophagus: a follow-up study based on 138 cases from a diagnostic variability study

The objective of endoscopic surveillance in Barrett esophagus (BE) is to assess the risk of subsequent development of invasive carcinoma. Criteria for morphologic evaluation of dysplasia, the presumed precursor lesion, have been established, although there are surprisingly few data in the literature correlating biopsy diagnosis of dysplasia with outcome. We collected follow-up information on 138 patients with BE whose initial endoscopic biopsy specimens had been selected for submission in an interobserver variability study performed by 12 pathologists with special interest in gastrointestinal pathology and reviewed blindly twice each by all the participants. Cases were scored as BE with no dysplasia, atypia indefinite for dysplasia (IND), low-grade dysplasia (LGD), high-grade dysplasia (HGD), intramucosal carcinoma, and frankly invasive carcinoma, thus generating 24 scores on each biopsy specimen. Clinical follow-up was obtained and correlated with both the submitting diagnoses and majority diagnoses. Kaplan-Meier statistics were used to compare both the submitting and majority diagnoses with outcome using detection or documentation of invasive carcinoma as the endpoint. Using the submitting diagnoses, no invasive carcinomas were detected in 44 cases diagnosed as BE (median follow-up, 38.5 months). Carcinomas were detected in 4 of 22 (18%) cases submitted as IND (median progression-free survival of 62 months), in 4 of 25 (15%) cases of LGD (median progression-free survival of 60 months), in 20 of 33 cases of HGD (median progression-free survival, 8 months), and all 13 (100%) cases submitted as adenocarcinoma. Grade on initial biopsy correlated significantly with progression to invasive carcinoma (log-rank P =.0001). Majority diagnosis was achieved in 99 of the cases. Using the majority diagnoses, no invasive carcinomas were found in 50 cases of BE (median follow-up, 48 months), and carcinomas were detected in 1 of 7 (14%) IND cases (80% progression-free survival at 2 months), 3 of 15 (20%) LGD (median progression-free survival, 60 months), 9 of 15 (60%) HGD (median progression-free survival, 7 months), and all 12 (100%) carcinoma. Initial grading again correlated significantly with progression to invasive carcinoma (log-rank P =.0001). However, there were 39 cases without a majority diagnosis. Among these, no carcinomas developed in 8 cases with an average score between BE and IND. Carcinomas were detected in 9 of 21 (43%) cases with an average score between IND and LGD, and 7 of 10 (70%) cases with an average score between LGD and HGD. There were ulcers in 8 of 39 cases (20%) of the "no-majority" group and in 13 of 99 (13%) of the majority cases. Of 21 total ulcerated cases, cancer was demonstrated in 15 (71%) of these on follow-up. These data support combining the IND and LGD categories for surveillance purposes. Cases without dysplasia may be followed up conservatively. The data obtained from submitted diagnoses as opposed to those from blind review suggest that knowledge of the clinical findings aids in diagnosis. The data also support the assertion that HGD is strongly associated with invasive carcinoma. Rebiopsy of ulcerated areas should be considered because they may harbor malignancy. Histologic grading of dysplasia using established criteria is a powerful prognosticator in BE. HUM PATHOL 32:379-388.

Reproducibility of the diagnosis of dysplasia in Barrett esophagus: a reaffirmation

Morphologic assessment of dysplasia in Barrett esophagus, despite limitations, remains the basis of treatment. We rigorously tested modified 1988 criteria, assessing intraobserver and interobserver reproducibility. Participants submitted slides of Barrett mucosa negative (BE) and indefinite (IND) for dysplasia, with low-grade dysplasia (LGD) and high-grade dysplasia (HGD), and with carcinoma. Two hundred fifty slides were divided into 2 groups. The first 125 slides were reviewed, without knowledge of the prior diagnoses, on 2 occasions by 12 gastrointestinal pathologists without prior discussion of criteria. Results were analyzed by kappa statistics, which correct for agreement by chance. A consensus meeting was then held, establishing, by group review of the index 125 slides, the criteria outlined herein. The second 125-slide set was then reviewed twice by each of the same 12 pathologists, and follow-up kappa statistics were calculated. When statistical analysis was performed using 2 broad diagnostic categories (BE, IND, and LG v HG and carcinoma), intraobserver agreement was near perfect both before and after the consensus meeting (mean kappa = 0.82 and 0.80). Interobserver agreement was substantial (kappa = 0.66) and improved after the consensus meeting (kappa = 0.70; P =.02). When statistical analysis was performed using 4 clinically relevant separations (BE; IND and LGD; HGD; carcinoma), mean intraobserver kappa improved from 0.64 to 0.68 (both substantial) after the consensus meeting, and mean interobserver kappa improved from 0.43 to 0.46 (both moderate agreement). When statistical analysis was performed using 4 diagnostic categories that required distinction between LGD and IND (BE; IND; LGD; HGD and carcinoma), the pre-consensus meeting mean intraobserver kappa was 0.60 (substantial agreement), improving to 0.65 after the meeting (P <.05). Interobserver agreement was poorer, with premeeting and postmeeting mean values unchanged (kappa = 0.43 at both times). Interobserver agreement was substantial for HGD/carcinoma (kappa = 0.65), moderate to substantial for BE (kappa = 0.58), fair for LGD (kappa = 0.32), and slight for IND (kappa = 0.15). The intraobserver reproducibility for the diagnosis of dysplasia in BE was substantial. Interobserver reproducibility was substantial at the ends of the spectrum (BE and HG/carcinoma) but slight for IND. Both intraobserver and interobserver variation improved overall after the application of a modified grading system developed at a consensus conference but not in separation of BE, IND, and LGD. The criteria used by the group are presented. HUM PATHOL 32:368-978.

Hepatic cryoablation-induced acute lung injury: histopathologic findings

We have previously shown that hepatic cryoablation (cryo), but not partial hepatectomy, induces a systemic inflammatory response, with distant organ injury and overproduction of NF-kappaB-dependent cytokines. Serum tumor necrosis factor-alpha (TNF-alpha) and macrophage inflammatory protein-2 (MIP-2) levels are markedly increased 1 h and beyond after cryo compared with partial hepatectomy where no elevation occurs. NF-kappaB activation (by electrophoretic mobility shift assay) is strikingly increased in the noncryo liver (but not in the lung) at 30 min and in both the liver and lung tissue 1 h after cryo, returning to the baseline by 2 h and beyond. The current study investigated the histopathologic changes associated with cryoablation-induced acute lung injury. Animals underwent 35% hepatic resection or a similar volume hepatic cryo and were sacrificed at 1, 2, 6, and 24 h. Pulmonary histologic features were assessed using hematoxylin and eosin and immunoperoxidase staining with a macrophage-specific antibody (anti-lysozyme, 1:200 dilution, Dako, Carpinteria, CA). The following features were graded semiquantitatively (0-3): perivascular lymphoid cuffs, airspace edema and hemorrhage, margination of neutrophils within pulmonary vasculature, and the presence of macrophages with foamy cytoplasm in the pulmonary interstitium. Hepatic resection (n = 21) resulted in slight perivascular edema at 1, 2, 6, and 24 h post-resection, but there were no other significant changes. Pulmonary findings after hepatic cryo (n = 22) included prominent perivascular lymphoid cuffs 1 and 2 h following hepatic injury that were not present at any other time point (P 0.01). Marginating PMNs and foamy macrophages were more common after cryo at all time points (P<0.05, cryo vs resection). Severe lung injury, as evidenced by airspace edema and parenchymal hemorrhage, was present in four of six (67%) animals at 24 h (P 0.03). In follow-up studies immediate resection (n = 15) of the cryo-treated liver prior to thawing prevented the pulmonary changes. The findings of pulmonary perivascular interstitial macrophages 2 h following hepatic cryo suggests that hepatic cytokine production may induce downstream recruitment of pulmonary macrophages, which may contribute to subsequent severe lung injury. This study suggests that a soluble mediator from direct liver injury leads to neutrophilic lung inflammation and this is associated with the thawing phase of cryoablation.

Contemporary trends and practice strategies in pediatric occupational and physical therapy

This paper identifies and reflects on recent trends in pediatric occupational therapy and physical therapy practice. These trends were initially identified by the student authors for a Maternal and Child Health (MCH) leadership seminar, which was conducted as part of the postprofessional graduate program in physical therapy at the University of Washington. Trends were then reviewed and discussed among the student and faculty authors. Consensus was reached on the most important trends, which were subsequently summarized in this paper. The first part of the paper reviews the impact of these trends on current and future clinical practices in health, educational, and community-based settings. The second part of the paper offers proposed directions to meet the challenges presented by the trends in four key areas; (1) research, (2) professional education, (3) enhancing family-centered care, and (4) advocacy.

Targeted disruption of the Kvlqt1 gene causes deafness and gastric hyperplasia in mice

The KvLQT1 gene encodes a voltage-gated potassium channel. Mutations in KvLQT1 underlie the dominantly transmitted Ward-Romano long QT syndrome, which causes cardiac arrhythmia, and the recessively transmitted Jervell and Lange-Nielsen syndrome, which causes both cardiac arrhythmia and congenital deafness. KvLQT1 is also disrupted by balanced germline chromosomal rearrangements in patients with Beckwith-Wiedemann syndrome (BWS), which causes prenatal overgrowth and cancer. Because of the diverse human disorders and organ systems affected by this gene, we developed an animal model by inactivating the murine Kvlqt1. No electrocardiographic abnormalities were observed. However, homozygous mice exhibited complete deafness, as well as circular movement and repetitive falling, suggesting imbalance. Histochemical study revealed severe anatomic disruption of the cochlear and vestibular end organs, suggesting that Kvlqt1 is essential for normal development of the inner ear. Surprisingly, homozygous mice also displayed threefold enlargement by weight of the stomach resulting from mucous neck cell hyperplasia. Finally, there were no features of BWS, suggesting that Kvlqt1 is not responsible for BWS.

Hepatic stellate cell activation in nonalcoholic steatohepatitis and fatty liver

Factors associated with the development of fibrosis in nonalcoholic steatohepatitis (NASH) are largely unknown, although an association with increased hepatic iron has been suggested. Hepatic stellate cells are the principal collagen-producing cells in many liver diseases and when activated express alpha-smooth muscle actin (alpha-SMA). Hepatic stellate cell activation and association with fibrosis, necroinflammatory activity, steatosis, and stainable iron in 60 cases of NASH and 16 cases of steatosis were evaluated. All 76 patients were obese or had other risk factors for NASH. All biopsy specimens were stained for alpha-smooth muscle actin to evaluate the pattern of hepatic stellate cell activation and were evaluated for inflammatory activity (0 to 3), fibrosis (0 to 4), and stainable iron stores (0 to 4). The zonal location of activated stellate cells was recorded, and the degree of activation was graded as high-grade or low-grade based on the percentage of lobular alpha-SMA+ cells. Activated stellate cells were identified in the hepatic lobule in 74 of 76 biopsy specimens and graded as low-grade in 26 and high-grade in 48. Zone 3 was involved in 72 of 74 positive cases, and in 33 cases, the activated stellate cells were preferentially located in zone 3. The degree of stellate cell activation correlated with fibrosis but not with inflammatory activity, severity of steatosis, or stainable iron. In most cases, the degree of stellate cell activation paralleled the degree of hepatic fibrosis, but in 25 cases, the degree of hepatic stellate cell activation was greater than expected, raising the question of whether such patients are at risk for disease progression.

Prevalence and prognostic significance of neuroendocrine cells in esophageal adenocarcinoma

Neuroendocrine differentiation is common in adenocarcinomas of the stomach and colon and may be associated with a slightly better prognosis in gastric adenocarcinoma. We studied neuroendocrine differentiation in esophageal adenocarcinomas and associated Barrett's esophagus (BE) to determine association with patient outcome. Fifty-eight cases of esophageal adenocarcinoma (15 biopsies, 43 resections) from 52 patients were stained with a monoclonal antibody to chromogranin (CG). Medical records were reviewed for tumor stage, response to therapy, and patient survival. Thirty-two patients received radiation and chemotherapy, and four received radiation. Twelve of 58 (20.7%) esophageal adenocarcinomas contained scattered CG-positive cells. Tumors with CG-positive cells were moderately to poorly differentiated, and many consisted of large cribriform glands, similar to intestinal-type adenocarcinomas. One case of small cell carcinoma of the esophagus was weakly CG positive; another was negative. Neuroendocrine differentiation was retained in lymph node metastases in two cases but lost in three other cases. In 10 CG-negative primary tumors, lymph node metastases were also negative. For five of six patients with paired biopsy/resection specimens, no CG-positive cells were seen in either specimen; one patient had CG-positive cells only in the resection. There was no difference in tumor stage at surgery or survival time between CG-positive and CG-negative tumors. BE was present in 34 cases and contained CG-positive cells in 21 of 34 (61.8%). Low-grade dysplasia contained CG-positive cells in 11 of 14 cases (78.6%) and high-grade dysplasia in 3 of 6 cases. Fourteen of 21 (66.7%) adenocarcinomas associated with CG-positive BE were negative for CG. In summary, neuroendocrine differentiation is common in BE and is retained in low- and high-grade dysplasia but is usually lost in esophageal adenocarcinoma. The presence of scattered neuroendocrine cells does not affect patient outcome.

Acute lung injury after hepatic cryoablation: correlation with NF-kappa B activation and cytokine production

BACKGROUND

Previous clinical reports have documented multisystem organ injury after hepatic cryoablation. We hypothesized that hepatic cryosurgery, but not partial hepatectomy, induces a systemic inflammatory response characterized by distant organ injury and overproduction of nuclear factor kappa B (NF-kappa B)-dependent, proinflammatory cytokines.

METHODS

In this study, rats underwent either cryoablation of 35% of liver parenchyma or a similar resection of left hepatic tissue. Serum tumor necrosis factor-alpha and macrophage inflammatory protein-2 levels and NF-kappa B activation were assessed by electrophoretic mobility shift assay at 30 minutes 1, 2, 6, and 24 hours after either procedure.

RESULTS

Cryoablation of 35% of liver (n = 22 rats) resulted in lung injury and a 45% mortality rate within 24 hours of surgery, whereas 7% treated with 35% hepatectomy (n = 15 rats) died during the 24 hours after surgery (P < .05, cryoablation vs hepatectomy). Serum tumor necrosis factor-alpha and macrophage inflammatory protein-2 levels were markedly increased in rats (n = 10 rats) 1 hour after hepatic cryoablation compared with rats that underwent partial hepatectomy (P < .005). We evaluated NF-kappa B activation by electrophoretic mobility shift assay in nuclear extracts of liver and lung after cryosurgery and found that NF-kappa B activation was strikingly increased in the liver but not the lung at 30 minutes and in both organs 1 hour after cryosurgery, and returned to baseline in both organs by 2 hours. In rats undergoing 35% hepatectomy, no increase in NF-kappa B activation was detected in nuclear extracts of either liver or lung at any time point.

CONCLUSIONS

These data show that hepatic cryosurgery results in systemic inflammation with activation of NF-kappa B and increased production of NF-kappa B-dependent cytokines. Our data suggest that lung injury and death in this animal model is mediated by an exaggerated inflammatory response to cryosurgery.

Concurrent paclitaxel and thoracic irradiation for locally advanced esophageal cancer

Esophageal cancer is a major cause of morbidity and mortality worldwide. Although patients often present with apparently resectable disease, systemic spread frequently occurs before the development of symptoms and detection of tumor. The use of combined chemoradiation therapy, particularly before resection, appears to prolong survival and increase cure rates in certain histologic subtypes. Four randomized phase III trials compared preoperative chemoradiotherapy plus surgery with surgery alone. In trials including only patients with squamous histology, no improvement in survival was observed with preoperative chemoradiation therapy; however, in a trial including only patients with adenocarcinoma histology, improved median and overall survival were observed. Paclitaxel has been evaluated as a single agent in a phase II trial in previously untreated patients with locally advanced unresectable or metastatic esophageal cancer; the overall response rate was 32% and median survival was 13.2 months. Paclitaxel-based combinations also have been evaluated in esophageal cancer; particularly encouraging preliminary results have been achieved with paclitaxel/cisplatin/5-fluorouracil. Because paclitaxel is a potent radiosensitizer, it also has been evaluated in combination with radiation therapy for esophageal and other thoracic cancers, alone and in combination with other chemotherapeutic agents. Preliminary results suggest that neoadjuvant therapy with paclitaxel-based combinations (including 5-fluorouracil and cisplatin) and radiation is highly active, with variable toxicity. A goal of future trials is to assess paclitaxel-based combined modality therapy in combination with other new chemotherapeutic agents.

Ki-1+ large-cell anaplastic lymphoma after Ewing sarcoma

PURPOSE

A large cell anaplastic lymphoma that developed after treatment of a Ewing sarcoma (ES) is described.

PATIENT

An 11-year-old girl with a pelvic ES developed a large cell, Ki-1+, anaplastic lymphoma in the same anatomic location 10 months after multimodal therapy.

RESULTS

ES recurred in the primary site 16 months after allogeneic marrow transplantation and 3.5 years after initial diagnosis, but the patient remains in remission from her lymphoma.

CONCLUSION

The occurrence of lymphoma and ES in a short time interval in the same patient is very unusual. Whether etiologic factors other than chemoradiotherapy, including genetic disposition, play a role remains to be elucidated.

Liver regeneration is transiently impaired in urokinase-deficient mice

To test the hypothesis that urokinase-type plasminogen activator (uPA) plays an important role in liver regeneration in vivo, partial hepatectomy was performed on wild-type and uPA-deficient (uPA-/-) mice. Mice were studied at 24, 44, and 96 h and at 8 days and 4 wk post-partial hepatectomy for evidence of regeneration, as measured by mitotic indexes and [3H]thymidine incorporation. In wild-type mice, thymidine incorporation peaked at 44 h and this index was reduced by 47% in uPA-/- mice (P = 0.02). By 8 days, however, liver mass was comparable in both groups. Histological analysis revealed the presence of focal areas of fibrin deposition and cellular loss by 24 h that were more severe and prevalent in uPA-/- mice than in wild-type mice (62 and 23%, respectively; chi2 = 3.939, P = 0.047). In contrast, regeneration was not impaired in uPA receptor (uPAR)-deficient mice at 24 and 44 h. Taken together, these data indicate that uPA, independent of its interaction with the uPAR, plays an important role in liver regeneration in vivo.

Expression of beta-catenin, alpha-catenin, and E-cadherin in Barrett's esophagus and esophageal adenocarcinomas

Loss of expression and function of the E-cadherin/catenin membrane complex can result in loss of cell adhesion and contribute to invasive or metastatic potential in carcinomas. The aim of this study was to examine the expression of alpha- and beta-catenin and E-cadherin in Barrett's esophagus with and without dysplasia and in esophageal adenocarcinomas and to identify any relationship with tumor growth pattern and clinical outcome. Immunoperoxidase staining for alpha- and beta-catenin and E-cadherin was performed on specimens of Barrett's esophagus with and without dysplasia and on 54 esophageal adenocarcinoma specimens. Membranous staining for all of the components was seen in normal gastric and esophageal mucosa. Abnormal expression of beta-catenin, alpha-catenin, and E-cadherin was significantly associated with higher degrees of dysplasia in Barrett's esophagus. Fourteen of 16 cases of high grade dysplasia and 7 of 7 cases of intramucosal carcinoma showed abnormal expression of beta-catenin, compared with 3 of 6 cases indefinite for dysplasia and 11 of 17 cases with low grade dysplasia (P = 0.022). Similar results were seen for expression of alpha-catenin (P < .01) and E-cadherin (P = .049). In esophageal adenocarcinomas, preserved expression of these proteins occurred more frequently in well-differentiated tumors; abnormal expression was more common in diffusely infiltrative poorly differentiated tumors that did not form glands. Focal nuclear staining for beta-catenin was present in two high-grade dysplasias, two intramucosal carcinomas, and five adenocarcinomas. No survival advantage was demonstrated for patients whose tumors retained expression of these cell adhesion components. In conclusion, abnormal expression of the E-cadherin/catenin membrane complex is common in esophageal adenocarcinoma and occurs early in the dysplasia/carcinoma sequence in Barrett's esophagus, indicating that disturbances in this cell adhesion complex might be important in tumorigenesis and tumor progression in this disorder.

Alterations in colonic mucosal vessels in patients with cirrhosis and noncirrhotic portal hypertension

Changes in intestinal mucosal microvasculature as a cause of lower gastrointestinal hemorrhage in patients with portal hypertension have been well documented clinically, but the analogous histomorphological changes have not been well characterized. The goal of this study was to evaluate qualitative and quantitative changes in colonic mucosal vessels in patients with cirrhosis or clinically evident portal hypertension and to correlate these changes with endoscopic and clinical findings. Colon biopsy or resection specimen slides from 46 patients with biopsy-proven cirrhosis (44 patients) or noncirrhotic portal hypertension (two patients) were reviewed. Immunoperoxidase stain for CD34 antigen was used to facilitate visualization of mucosal vessels, and vessel diameter was measured with a micrometer. Patients with inflammatory bowel disease were excluded. Twenty-four normal colon biopsy specimens served as controls. Mucosal vessels were divided into superficial, intermediate, and deep layers. As a group, the cirrhotic patients had a significantly higher mean diameter of vessels in all three layers. Qualitatively, increased numbers of small vessels and prominent branching were noted, especially in the superficial and intermediate layers. Tortuous, thick-walled vessels, suggesting arterialization of venules, were present in some cases. Eleven patients had endoscopic findings suggestive of vascular abnormalities, including erythematous mucosal patches, red macules, and telangiectasias. Eighteen had esophageal varices, and five had portal gastropathy. Nineteen patients had gastrointestinal (GI) bleeding, localized to the lower GI tract in 11. These qualitative and quantitative findings suggest that colonic mucosal vascular lesions are common in portal hypertension and may represent a potential source of clinically significant lower GI hemorrhage in these patients.

Can experimental models of rodent implantation glioma be improved? A study of pure and mixed glioma cell line tumours

To evaluate the hypothesis that co-implantation of different rodent glioma cell lines might result in experimental brain tumours that more closely resemble human gliomas the neuropathology and immunocytochemical features of implantation gliomas derived from single cell lines (C6, A15A5, F98), two cell lines admixed 50:50 prior to implantation (C6 + F98 and C6 + A15A5) and three cell lines equally admixed (C6 + A15A5 + F98) was studied in the adult Wistar rat. Tumours grew consistently following implantation of the single and the two admixed cell lines, however tumour growth following triple mix implantation was considerably and consistently impaired. The tumours derived from admixed cell lines showed regional heterogeneity with areas characteristic of both the primary cell lines. Foci of lymphocytic infiltrates, tumoural necrosis, often with pseudopallisading, and peritumoural edema were consistent features of all tumours. Limited parenchymal and more extensive perivascular tumoural invasion was seen predominantly in tumours containing the C6 cell line. There were no significant differences in GFAP, vimentin and HSP70 staining between the mixed tumours, although the pure F98 and A15A5 tumours were, unlike the pure C6 gliomas, S-100 negative. Using PCNA expression as a measure of the tumour proliferation all except the tumours derived from the three cell lines mix, which had a staining index of 7-10%, had focal staining indices in viable tumour of between 40-80%. There was focal positive staining in both perilesional brain and in regions of all tumours for the macrophage markers ED-1 and ED-2. None of the three cell lines stained in vitro for either ED1 and ED2 but all were constitutively positive in vitro for OX-6, a proposed marker for antigen presenting cells. The macrophage and lymphocytic response suggest a vigorous but largely ineffective immunological response had been mounted against all tumours. The consistent failure of the triple mix tumours to grow is unexplained. This work has shown the feasibility of producing 'mixed' cell line experimental gliomas by combining two cell lines at the time of innoculation. However, the relative failure to produce (i) mixed tumours that have properties not inherent to either parent cell line and (ii) implantation glioma with three cell lines suggest there are limits to this approach. Admixture of cell lines at the time of implantation therefore does not make experimental glioma models that more closely resemble natural gliomas, and also has some particular disadvantages. This experimental approach is therefore not recommended for use in the study of tumour biology and in evaluating the effectiveness of novel therapies.

Functional studies on the anti-pathoangiogenic properties of CM101

Group B streptococcus (GBS) isolated from human neonates diagnosed with sepsis and respiratory distress produces a polysaccharide exotoxin (CM101) which has been previously described as GBS toxin. CM101 infused i.v. into tumor-bearing mice causes rapid tumor neovascularitis, infiltration of inflammatory cells, inhibition of tumor growth and tumor apoptosis. CM101 has successfully completed phase I studies in refractory cancer patients with very encouraging results. We have now demonstrated a mechanism of action for CM101. Using a normal mouse tumor model, we have examined tumor and normal tissues which were harvested at 0, 5, 15, 30 and 60min post-infusion of either CM101 or dextran. We present evidence that CM101 is rapidly (within the first 5min) bound to the tumor neovasculature. Complement is activated by the alternative pathway (C3) and leukocytes start to infiltrate the tumor within the first 5min. Through RT-PCR and immunohistochemical techniques, we demonstrate that proinflammatory cytokines, interleukin-6 and tumor necrosis factor (TNF)-alpha, are up-regulated in infiltrating leukocytes and TNF receptor 2 is up- regulated in the targeted tumor neovasculature. Combined, these events constitute possible explanations for the observed pathophysiology of tumor ablation.

RT in situ PCR for the detection of mRNA transcripts of Fas-L in the immune-privileged placental environment

Rapid and reproducible detection of RNA in cells and tissue sections is routinely accomplished using in-situ hybridization technique provided that the target number of mRNA copies is above a minimum number. Detection of low copy transcripts is problematic when threshold detection occurs below clear signal resolution or alternatively, when technical problems result in background noise which occludes clear signal. RT in-situ PCR methodology utilizes both the power and specificity of PCR to amplify target whose localization is subsequently detected at the cellular level. RT in-situ PCR methods routinely involve a two-step methodology. mRNA copies are initially transcribed into cDNA. This step is followed by a separate PCR step wherein amplification of the newly synthesized cDNA takes place. A simplified one-step procedure biochemically compartmentalizes these sequential steps within a single applications methodology using the enzyme rTth. This method was successfully applied to detect and localize mRNA transcripts for Fas ligand within the immune privileged placental environment and to provide verification of immunohistochemical localization of gene product.

Gastric graft-versus-host disease: a blinded histologic study

Acute graft-versus-host disease (GvHD) of the upper gastrointestinal (GI) tract is common after allogeneic bone marrow transplantation (BMT). However, diagnosis cannot be made on clinical presentation and endoscopic findings alone, because these are nonspecific, and histologic confirmation is often desirable. The diagnosis of gastric GvHD is often based on subtle findings with considerable potential for variability in interpretation. Evaluation of the reproducibility of diagnosis and recognition of histologic features of gastric GvHD was based on blinded review of 56 gastric biopsies (24 from patients with allogeneic BMT or unrelated umbilical cord blood transplantation and 32 control biopsies from patients who did not undergo BMT, of whom eight had active GI cytomegalovirus [CMV] infection). Histologic criteria for GvHD were apoptosis and gland destruction, sparse inflammatory infiltrate, and granular eosinophilic debris in dilated glands. Seventeen patients (22 biopsies) were judged to have clinical GvHD on the basis of skin or liver involvement and GI symptoms without other known cause. Eighteen of these 22 gastric biopsies were classified as GvHD by at least two of the three pathologists on initial review. Blinded histologic diagnosis of GvHD had a positive predictive value of 69%, a sensitivity of 82%, and specificity of 76%. False-positive results occurred in CMV gastritis, human immunodeficiency virus (HIV) infection, primary immunodeficiency, and after renal transplantation. Of individual features, granular debris in glands was a specific (94% specificity), but insensitive (41% sensitivity) marker for GvHD. Distinction between GvHD and CMV infection can be difficult, and GvHD can be confused with changes seen in HIV infection and other immunodeficiency states.

Peribiliary vascular plexus in primary sclerosing cholangitis and primary biliary cirrhosis

The peribiliary vascular plexus plays an important role in physiology of bile flow. Disturbance of the microcirculation may contribute to ductal injury, but little is known about alterations in the vascular supply of small bile ducts in liver disease. Immunoperoxidase stains for vascular endothelium (Ulex europaeus, factor VIII-related antigen, CD34) were used to study the peribiliary vascular plexus in 20 cases of primary sclerosing cholangitis (PSC) and 27 cases of primary biliary cirrhosis (PBC), two diseases characterized by bile duct destruction. Normal liver from 10 autopsy cases of sudden cardiac death was used as a control. Interlobular bile ducts (20- to 80-microm diameter) were identified on AE1/AE3 immunostain; vessels adjacent to the basement membrane of these ducts were counted. Normal interlobular bile ducts had an average of 2.15 vessels per duct (range, 1.68 to 2.71). Few PBC or PSC cases had a normal number of peribiliary vessels. There was a trend toward vasopenia at higher stage, although vascular loss was noted in early stages as well. The pattern of vascular loss was different for the two diseases; in PSC, the periductal capillaries were often preserved but were pushed away from the basement membrane by concentric deposits of collagen. Small residual vessels could be identified within fibrous scars of obliterated bile ducts in PSC. In 4 stage 3 or 4 PSC cases with little bile duct injury, vessel/duct ratio approached normal levels. In PBC, vessels were obliterated in areas of granulomatous inflammation and heavy lymphocytic infiltrate around bile ducts. In conclusion, loss of peribiliary vessels is common in PSC and PBC. Vessel loss is seen in early stages and may contribute an element of ischemia to continued small bile duct loss but is probably secondary to the inflammatory process.

Expression of cell adhesion molecule CD44 in primary tumors of the liver: an immunohistochemical study

CD44, a widely distributed integral membrane protein, has been implicated in tumor invasion and metastatic spread in some human carcinomas and lymphomas. In this study, 35 cases of hepatocellular carcinoma from 32 patients (11 cholangiocarcinomas, 9 hepatic adenomas, and 5 cases of focal nodular hyperplasia, a non-neoplastic lesion) were examined by immunohistochemical methods for expression of CD44. The mouse monoclonal antibody A3D8 was used on formalin-fixed, paraffin-embedded tissue; this antibody does not distinguish between standard CD44 and splice variants. Positive membrane staining was seen in 13 of 35 cases of hepatocellular carcinoma (12 of 32 patients), 8 of 11 cases of cholangiocarcinoma, and 1 of 9 cases of hepatic adenoma. The strongest staining for CD44 was seen in two cases of fibrolamellar carcinoma, but CD44 expression was otherwise not related to degree of tumor differentiation. All five cases of focal nodular hyperplasia were negative for CD44. In non-neoplastic liver, hepatocytes were negative; sinusoidal lining cells and portal lymphocytes were positive; bile ducts and proliferating bile ductules were focally positive in some cases. Anatomic stage at time of presentation was similar in both groups of patients, with most patients presenting with stage III or IV disease. A trend towards slightly longer survival in patients whose hepatocellular carcinomas were CD44 negative was noted. These results show that aberrant CD44 expression is present in a subset of hepatocellular carcinomas and in most cholangio-carcinomas. The relationship between CD44 expression and tumor spread is unclear in this group of tumors, but is unlikely to be a simple association between CD44 expression and metastatic potential.

Endoscopic tattoo agents in the colon. Tissue responses and clinical implications

Laparoscopic surgery frequently requires tattooing of endoscopically identified sites for localization during surgery. Some tattooing agents cause serious tissue injury, which must be recognized in pathologic examination. Seven surgically resected colons were reviewed after injection with methylene blue or India ink at intervals of 1 day to 7 weeks before surgery. Early reactions to India ink included necrosis, edema, and neutrophilic infiltration in the submucosa and muscularis propria. Vessels were inflamed but without fibrinoid necrosis. Early reactions to methylene blue included ischemic ulceration, necrosis, and eosinophilic infiltration in the submucosa as well as fibrinoid necrosis of vessel walls. In the repair of methylene-blue injury, obliterative intimal fibrosis was seen in vessels. Such changes were absent in the colons injected with India ink. The India ink remained remained visible with the naked eye and microscopically 7 weeks after injection. Methylene blue was not grossly visible 7 days after injection, and only microscopic particles of pigment remained in widely scattered macrophages. In light of these findings, the amount of ink injected should be minimized and the injection site should be completely resected at surgery. Methylene blue is a poor tattoo agent, but its occasional use continues, and pathologists should recognize the resulting reaction.

Gastrointestinal pathology in patients with common variable immunodeficiency and X-linked agammaglobulinemia

Review of the medical records of 43 patients with common variable immunodeficiency (CVID) and 23 patients with X-linked agammaglobulinemia (XLAG) revealed a high incidence of chronic gastrointestinal complaints, most commonly diarrhea. Thirty-eight biopsies, four small-bowel resection specimens, and one autopsy from 10 patients with CVID and one patient with XLAG showed a wide range of abnormalities. A pattern resembling acute graft-versus-host disease, with apoptotic bodies and lymphocytes in crypts, was seen in the stomach (four patients), small bowel (three patients), and colon (three patients). Small-bowel specimens from three CVID patients with malabsorption showed mild to severe villous atrophy. Three CVID patients had Giardia in biopsies. Two cases of small bowel lymphoma associated with nodular lymphoid hyperplasia were identified in CVID patients. One patient's small bowel contained foamy histiocytes in the lamina propria, resembling Whipple's disease or chronic granulomatous disease, with numerous apoptotic bodies in crypts. Ultrastructurally, the histiocytes contained cellular debris. The patient with XLAG had recurrent fissuring necrosis of small bowel resembling Crohn's disease; a patient with CVID had colitis with features similar to ulcerative colitis. Poorly formed granulomas were seen in the stomach (one CVID patient) and the colon (two CVID patients). Lymphocyte populations were dominated by T cells; B cells were scarce except in lymphoid follicles in CVID patients with nodular lymphoid hyperplasia. Patients with CVID and XLAG manifest a spectrum of abnormalities in the gastrointestinal tract, with patterns superficially resembling graft-versus-host disease, inflammatory bowel disease, and Whipple's disease, but often lacking some of the diagnostic features of the diseases. Many of the CVID patients with chronic gastrointestinal complaints (62%) also had evidence of autoimmune phenomena, suggesting that in some patients the inflammatory process in the gastrointestinal tract has an autoimmune component.

Expression of p53 in adenocarcinoma of the gallbladder and bile ducts

Point mutation of the p53 tumor suppressor gene appears to be an important event in tumor development and progression, and overexpression of the p53 gene product has been widely studied in a variety of neoplasms. Some point mutations of the p53 gene lead to an increase in half-life in the gene product, which accumulates in the nucleus and can be detected by immunohistochemical means. We studied overexpression of p53 protein in specimens from 12 patients with adenocarcinoma of the gallbladder, two gallbladders with epithelial dysplasia without carcinoma, eight carcinomas of the common bile duct, 13 hilar cholangiocarcinomas, and six peripheral cholangiocarcinomas. The monoclonal antibody Ab-2 (Oncogene Science) was used in conjunction with citrate microwave antigen retrieval. Nuclear staining was scored as positive (graded 1 to 3, depending on number of positive nuclei) or negative. Overexpression of p53 protein was present in 7/12 (58%) gallbladder carcinomas, and was seen more often in moderately or poorly differentiated tumors. Intramucosal carcinoma adjacent to invasive carcinoma was positive in three cases, although fewer cells stained than in the carcinoma. Two cases of low-grade dysplasia not associated with carcinoma were negative. Expression of p53 was not an independent prognostic factor when survival was related to grade and stage of tumor. Three of eight (38%) common bile duct carcinomas and 5/13 (38%) hilar cholangiocarcinomas were positive for p53. Slightly fewer (2/6, 33%) peripheral cholangiocarcinomas were positive. No difference in survival relative to p53 expression was demonstrated.

Anaplastic renal cell carcinoma following neuroblastoma

Renal cell carcinoma is unusual in children. We report a case of anaplastic renal cell carcinoma arising in a 7-year-old girl following treatment for Stage III neuroblastoma. The renal cell carcinoma has unusual histologic and ultrastructural features, which are discussed. The case is further unusual in that few children with advanced stage neuroblastoma survive long enough to develop second malignant neoplasms.

Secondary tumors of the gastrointestinal tract: surgical pathologic findings and comparison with autopsy survey

Secondary tumors of the gastrointestinal (GI) tract are unusual but are probably more common than clinically suspected. Comparison of surgical pathologic findings and autopsy experience over a 14-yr period revealed a different spectrum of tumors, which may reflect clinical practice issues and the pathophysiology of individual tumors. Seventy-three surgical resection or biopsy cases with clinically evident secondary tumors were compared with 108 autopsy cases with secondary malignancies involving the GI tract. The most common tumors in surgical specimens were melanoma (22 cases), ovary (11 cases), bladder (eight cases), breast (six cases), and lung (five cases). The most common primary tumors at autopsy were lung (21 cases), gynecologic malignancies (18 cases), breast (14 cases), and pancreas (nine cases). In most cases, routine histologic examination yielded clues to the primary tumor. Metastatic breast carcinoma cases had a high potential for misinterpretation because most metastases consisted of infiltrating strands of pleomorphic cells without gland formation. Signet ring cells were present in most metastases (all six surgical cases and seven of 14 autopsies), regardless of the histologic type of the primary breast carcinoma. The time from diagnosis of the primary tumor to development of GI involvement varied widely, from presentation with GI metastases to more than 30 yr for metastatic malignant melanoma. Survival after development of GI involvement was generally poor, with most patients surviving less than 1 yr. However, long-term palliation may be achieved in a small subset of patients, chiefly those with single small bowel deposits of malignant melanoma or patients with breast carcinoma responsive to tamoxifen.

CT of the liver in patients with metastatic breast carcinoma treated by chemotherapy: findings simulating cirrhosis

OBJECTIVE

Although the hepatotoxic effects of systemic chemotherapy are well known, CT findings in the liver after systemic chemotherapy have received little attention in the literature. In some patients with breast carcinoma metastatic to the liver who have received chemotherapy, a morphologic pattern develops similar to that associated with cirrhosis. This pattern is characterized by a lobular hepatic contour, segmental volume loss, and enlargement of the caudate lobe. The purpose of this study was to describe the CT appearance of this pseudocirrhosis and to correlate it with pathologic findings.

MATERIALS AND METHODS

We reviewed 65 CT examinations of 22 patients with stage IV breast carcinoma with hepatic metastases, who were receiving systemic chemotherapy and for whom abdominal CT scans showed pseudocirrhosis. Nineteen of 22 patients had follow-up CT scans at intervals ranging from 1 to 15 months. Criteria for the diagnosis of pseudocirrhosis included a lobular hepatic contour, segmental volume loss, and enlargement of the caudate lobe. CT findings were correlated with pathologic findings in seven patients.

RESULTS

In all patients, CT scans showed retraction of the capsular surface of the liver (15 diffuse, seven focal) with a lobular margin, a finding also seen in advanced cirrhosis. The retraction occurred at the site of subjacent metastases. Findings evolved over 1-3 months. Six of seven patients had pathologic findings suggestive of nodular regenerative hyperplasia. No patients had pathologic evidence of cirrhosis.

CONCLUSION

In patients undergoing systemic chemotherapy for breast cancer metastatic to the liver, a pattern may develop that mimics the CT appearance of hepatic cirrhosis. Pathologic findings suggest nodular regenerative hyperplasia as a possible cause.

Tetracycline-induced bile duct paucity and prolonged cholestasis

Acute self-limited liver disease has been associated with tetracycline use. However, severe prolonged cholestatic hepatitis and bile duct paucity have not been previously attributed to tetracyclines. Hepatitis, characterized by prolonged jaundice, severe pruritus, and moderate increased transaminase values, occurred within 2 months of ingesting tetracyclines in two female patients. Serum bilirubin levels normalized 12 and 34 months after tetracycline ingestion. Liver histology revealed bile duct paucity, severe cholestasis, and minimal necrosis and inflammation. Tetracyclines may infrequently induce bile duct paucity and prolonged, severe, and reversible cholestasis.

Expression of the cell adhesion molecule CD44 in gastric adenocarcinomas

CD44, an integral membrane glycoprotein expressed by many cell types, serves as the principal transmembrane hyaluronate receptor and may be a determinant of metastatic and invasive behavior in carcinomas. The expression of CD44 in 23 gastric adenocarcinoma and 12 peptic ulcer disease (PUD) resection specimens and gastric carcinoma cell lines HS746t and KATO III was examined by immunohistochemistry using the murine monoclonal antibody A3D8 on formalin-fixed, paraffin-embedded tissue or cells. Western blot analysis of whole cell lysates of KATO III and HS746t cells showed protein bands at 85 to 90 kd with KATO III cells expressing an additional band at 145 kd. In normal stomach gastric epithelium was negative. In PUD foveolar epithelium was focally positive, but staining did not correlate with the extent of gastritis. In carcinoma cases intensity of staining was progressively stronger comparing intestinal metaplasia with dysplasia with intramucosal carcinoma. Invasive carcinoma was invariably more strongly positive than dysplasia or intramucosal carcinoma. Twelve adenocarcinomas were weakly positive and 11 were strongly positive. The staining intensity of metastases (12 cases) was the same or weaker than the primary tumor. For the 12 patients whose carcinomas were weakly positive, mean length of survival for the six who died was 23.3 months. Five of the 11 patients whose carcinomas strongly expressed CD44 died within the study period with a mean length of survival of 11.0 months. A key consequence of CD44 overexpression in gastric carcinomas may be development of the invasive phenotype and strong expression may indicate a poorer prognosis.

Pathology of the pancreas in severe combined immunodeficiency and DiGeorge syndrome: acute graft-versus-host disease and unusual viral infections

Review of autopsies of 28 children with severe combined immunodeficiency (SCID) or combined immunodeficiency (CID) and three with DiGeorge syndrome showed a high incidence of acute graft-versus-host disease (GVHD) in the pancreas. Acute GVHD (seven cases: four SCID, two CID, and one DiGeorge syndrome) was characterized by lymphocytes around large to medium ducts, damage to ductal epithelium (focal necrosis, reactive nuclear changes, inspissated secretions in duct lumens), and periductal edema. Changes were judged indeterminate but suspicious for GVHD when ductal damage was slight (six cases: three SCID, two CID, and one DiGeorge syndrome). All patients with pancreatic GVHD had received allogeneic bone marrow, fetal liver or thymus transplant, or nonirradiated blood products and had evidence of GVHD in other organs. Immunoperoxidase stain for HLA-DR showed strong-to-moderate staining of duct epithelium in two of four GVHD cases for which blocks were available. This change was nonspecific; weaker staining for HLA-DR was seen in cases with nonspecific abnormalities and in viral pancreatitis. Four cases had histological evidence of viral infection: two had cytomegalovirus pancreatitis, one had patchy parenchymal necrosis caused by adenovirus, and one had giant cell pancreatitis caused by parainfluenza virus. Mild nonspecific changes, such as focal fat necrosis or acinar dilatation, were seen in seven cases. One case had unexplained marked pancreatic atrophy and fibrosis. Acute pancreatic GVHD is not uncommon in autopsies of children with congenital immune deficiencies with GVHD of other organs; however, this finding may not have strong clinical implications in this group of patients. Careful attention to pancreatic ducts is necessary for diagnosis. Unusual viral pancreatitis may also be seen in this group, as well as nonspecific abnormalities.

Tissue culture of epithelium derived from Barrett's oesophagus

Barrett's oesophagus is a preneoplastic condition in which the squamous mucosa of the oesophagus is replaced by columnar epithelium. Epithelial cells of Barrett's oesophagus were isolated from resected oesophagus specimens by two methods not previously applied to the culture of Barrett's oesophagus cells. These techniques included trypsinisation of small fragments of mucosa, followed by plating in tissue culture dishes, and a direct tissue explant technique. A modified MCDB-153 growth medium was used. Primary trypsin technique cultures were plated on uncoated plastic, or plastic coated with type I collagen, type IV collagen, or fibronectin. Growth on type IV collagen and fibronectin plates was slower but produced less contamination from fibroblasts. By 20-40 days most cultures formed confluent monolayers made up of cells with epithelial morphology. The cells were cytokeratin positive, vimentin negative, and contained alcian blue positive vacuoles, confirming their epithelial origin and suggesting their derivation from Barrett's oesophagus. Electron microscopy showed tonofilaments, microvilli, and desmosomes. Cells proliferated through up to eight subcultures before growth slowed and cells showed senescent changes. This study shows that epithelial cells from Barrett's oesophagus can be grown by comparatively simple tissue culture techniques. These methods can provide sufficient material for a variety of molecular biology and biochemical studies of epithelial cells from Barrett's oesophagus.

Hepatic adenoma: MR characteristics and correlation with pathologic findings

OBJECTIVE

The purpose of this study was to describe the MR appearance of hepatic adenomas and correlate the MR imaging features with pathologic findings.

MATERIALS AND METHODS

MR examinations were performed in 14 patients with 66 hepatic adenomas. The diagnosis of hepatic adenoma was proved pathologically in nine patients (22 lesions). In five other patients (44 lesions), who had type I glycogen storage disease and were known to be at risk for hepatic adenomas, the diagnosis was established by repeated sonographic examinations that showed stability, reduction, or resolution of hepatic tumors. T1- and T2-weighted spin-echo MR images obtained at 1.5 T were retrospectively reviewed for the signal intensity of the lesions relative to liver, the signal pattern, the presence of a capsule, and the presence of hemorrhage. Histopathologic specimens (22 lesions) were reviewed for fat content (graded 0-3), the presence of a capsule, and the presence of hemorrhage.

RESULTS

On T1-weighted images, 51 (77%) of 66 lesions were hyperintense, 11 (17%) were hypointense, and four (6%) were isointense with respect to liver. On T2-weighted images, 49 (74%) of 66 lesions were hyperintense, 12 (18%) were isointense, and five (8%) were hypointense. Sixty-one (92%) of 66 lesions were heterogeneous. Eleven (17%) of 66 lesions were hemorrhagic. Of the 22 lesions reviewed histopathologically, 17 were hyperintense on T1-weighted images; 15 of these had a fat content of grade 2 or 3 and two had hemorrhage. All 15 lesions that had a fat content of grade 2 or 3 were hyperintense on T1-weighted images.

CONCLUSION

Hepatic adenomas have a variable MR appearance but most often are hyperintense with respect to liver on T1- and T2-weighted images. The high signal intensity often relates to the increased fat content of these lesions.