Plaque and remodeling markers in coronary thrombi

Background

Matrix Metalloproteinases (MMPs) and their inhibitors are considered to be of importance in development of atherosclerotic coronary artery disease. MMP-9 has been associated with unstable atherosclerotic plaques and rupture, as well as left ventricular remodeling after myocardial infarction (MI), whereas MMP-2 seems to be more related to progression of stable plaques. MMP activity is modulated by Tissue Inhibitors of Metalloproteinases (TIMPs). TIMP-1 has been associated with cardiac remodeling post MI, and TIMP-2 has been discussed to inhibit plaque development and destabilization. The extracellular MMP Inducer, EMMPRIN, stimulates both MMPs and TIMPs, and has been found upregulated on the surface of monocytes in patients with acute MI, and associated with MMP-9 activity.

Purpose

To study whether genes encoding MMP-2, MMP-9, TIMP-1, TIMP-2 and EMMPRIN are expressed in coronary thrombi and in circulating leukocytes from STEMI patients, and whether these are related to the degree of myocardial injury measured by troponin T, and time from symptoms to PCI.

Methods

Intracoronary thrombi were aspirated from 33 patients with ST-elevation myocardial infarction (STEMI) treated with primary PCI. The thrombi were snap-frozen in RNA-later solution for gene expression analyses. Peripheral blood samples with Pax-gene tubes were drawn at end of the PCI procedure. RNA was isolated from the thrombi and leukocytes, and the actual genes relatively quantified by RT PCR. Peak troponin T was collected from clinical records.

Results

Genes coding for the five different markers were present in 84–100% of the thrombi. Median peak troponin T was 3434 m/L. The expression of TIMP-1 in the thrombi correlated significantly to peak troponin T (r=0.393, p=0.026), and dividing peak troponin T values into quartiles, the median value of TIMP-1 mRNA in Q4 was 2.5-fold higher compared to Q1–3 (p=0.107). Peak troponin T also correlated to the expression of TIMP-1 in circulating leukocytes (r=0.469, p=0.006), and in Q4 of troponin T, the median value was 1.6-fold higher compared to Q1–3 (p=0.056). There were no significant correlations between the other measured genes and troponin T, and also no associations of any genes expressed in the thrombi or in circulating leukocytes to time from symptom to PCI (median 152 min).

Conclusion

Genes coding for MMP-2, MMP-9, TIMP-1, TIMP-2 and EMMPRIN were highly expressed in human coronary thrombi. The positive correlation between peak troponin T and the expression of TIMP-1 both in thrombi and in circulating leukocytes at time of PCI in patients with STEMI, may indicate that the role of TIMP-1 is important in cardiac remodeling immediately post-MI.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Stein Erik Hagens Foundation for Clinical Heart Research

The inflammasome signaling axis in thrombi from STEMI patients is related to degree of myocardial injury

Background

The NLRP3-inflammasome and the IL-6-pathways, i.e. the inflammasome signaling axis, seems to be central mechanisms in the inflammatory response related to myocardial reperfusion injury after revascularization. The beneficial results shown by treating MI-patients with canakunimab, an antibody blocking IL1-β, in the CANTOS trial*, and by treatment of NSTEMI patients with the IL6-receptor antagonist tocilizumab**, are looked upon as proof of concept for inflammasome inhibition.

Purpose

To study whether genes encoding inflammasome-related proteins are present in coronary thrombi and in circulating cells from STEMI patients, and whether these are related to the degree of myocardial injury as measured by troponin T, and time from symptoms to PCI.

Methods

Intracoronary thrombi were aspirated from 33 patients with STEMI treated with primary PCI. The thrombi were snap-frozen in RNA-later solution for gene expression analyses. Peripheral blood samples with Pax-gene tubes were drawn at end of the PCI-procedure. mRNA of NLRP3, caspase1, IL1-β, IL18, IL6, IL6-receptor (IL6-R) and gp130 were isolated from the thrombi and leukocytes in peripheral blood, and relatively quantified by RT PCR. Peak troponin was collected from clinical records.

Results

Genes coding for the 7 different markers were present in 76–100% of the thrombi. The expression of NLRP3 in thrombi significantly correlated to peak troponin T (r=0.468, p=0.024). Dividing peak troponin T values into quartiles, the median value of NLRP3 mRNA in Q4 was 2.0-fold higher compared to Q1–3 (p=0.012). Peak troponin T also correlated with the expression in circulating leukocytes of NLRP3 (r=0.420, p=0.0149) and IL1-β (r=0.394, p=0.023), and borderline to caspase1 (r=0.321, p=0.069) and IL18 (r=0.310, p=0.079).

IL6-R expression in thrombi correlated significantly to peak troponin T (r=0.434, p=0.019), with a 2.5-fold higher median level in Q4 vs Q1–3 of troponin T (p=0.017). gp130 expression in thrombi correlated inversely with peak troponin T (r=−0.398, p=0.050), as did IL6-R expression in circulating leukocytes (r=−0.421, p=0.015). There were no significant correlations between genes expressed in the thrombi and time from symptom to PCI (median 152 minutes), whereas genes for IL6 in circulating leukocytes correlated inversely (r=−0.385, p=0.027).

Conclusion

The inflammasome signaling pathway was actively regulated in coronary thrombi and in circulating leukocytes from patients with STEMI. Genes encoding NLRP3 and IL6-R were increasingly expressed in thrombi from patients with increased myocardial damage, measured by troponin T, supporting the beneficial effects of medically targeting this pathway.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Stein Erik Hagens Foundation for Clinical Heart Research

Effects of explant size on epithelial outgrowth, thickness, stratification, ultrastructure and phenotype of cultured limbal epithelial cells

Purpose

Transplantation of limbal stem cells is a promising therapy for limbal stem cell deficiency. Limbal cells can be harvested from either a healthy part of the patient’s eye or the eye of a donor. Small explants are less likely to inflict injury to the donor site. We investigated the effects of limbal explant size on multiple characteristics known to be important for transplant function.

Methods

Human limbal epithelial cells were expanded from large versus small explants (3 versus 1 mm of the corneal circumference) for 3 weeks and characterized by light microscopy, immunohistochemistry, and transmission electron microscopy. Epithelial thickness, stratification, outgrowth, ultrastructure and phenotype were assessed.

Results

Epithelial thickness and stratification were similar between the groups. Outgrowth size correlated positively with explant size (r = 0.37; P = 0.01), whereas fold growth correlated negatively with explant size (r = –0.55; P < 0.0001). Percentage of cells expressing the limbal epithelial cell marker K19 was higher in cells derived from large explants (99.1±1.2%) compared to cells derived from small explants (93.2±13.6%, P = 0.024). The percentage of cells expressing ABCG2, integrin β1, p63, and p63α that are markers suggestive of an immature phenotype; Keratin 3, Connexin 43, and E-Cadherin that are markers of differentiation; and Ki67 and PCNA that indicate cell proliferation were equal in both groups. Desmosome and hemidesmosome densities were equal between the groups.

Conclusion

For donor- and culture conditions used in the present study, large explants are preferable to small in terms of outgrowth area. As regards limbal epithelial cell thickness, stratification, mechanical strength, and the attainment of a predominantly immature phenotype, both large and small explants are sufficient.

Effect of Transportation on Cultured Limbal Epithelial Sheets for Worldwide Treatment of Limbal Stem Cell Deficiency

Limbal stem cell deficiency can be treated with transplantation of cultured human limbal epithelial cells (LEC). It can be advantageous to produce LEC in centralized labs and thereafter ship them to eye clinics. The present study used transport simulations of LEC to determine if vigorous shaking during transport altered the viability, morphology and phenotype during a 4 day-long storage of LEC with a previously described serum-free storage method. Inserts with LEC cultured on amniotic membranes were sutured to caps inside air-tight containers with generous amounts of 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES)-buffered minimal essential medium (MEM). The containers were distributed among the following testing conditions: 6 hours with full containers, 36 hours with full containers, 36 hours with container three quarters full of medium, and 36 hours with container full of medium containing a shear-protecting agent (Pluronic-F68). Compared to stored, but non-transported controls, no statistically significant changes in viability and immunohistochemical staining were observed. The epithelial sheets remained intact. However, an air-liquid interface in the containers reduced the number of desmosomes and hemi-desmosomes compared to the controls. In conclusion, cultured LEC sheets appear to endure vigorous shaking for at least 36 hours if the container is full.

Febrile Illness and Intravenous Antimalarial Treatment at a District Hospital in Cameroon

BACKGROUND

Malaria is one of the most common causes of mortality worldwide. The World Health Organization (WHO) has recently recommended that treatment should be guided by a laboratory diagnosis. The aim of this study is to explore patient and health care factors associated with intravenous antimalarial treatment of malaria test-negative patients at a district hospital in a malaria endemic area.

STUDY DESIGN

A cross-sectional study of 91 patients admitted for intravenous antimalarial treatment was done at a district hospital in northern Cameroon in July and August 2010. Socio-cultural and clinical factors were studied in relation to quality blood smear results.

RESULTS

Thirty-two per cent of all intravenous antimalarials were administered to patients with a negative malaria test. Test negative patients older than 40 years of age received significantly more often intravenous antimalarials than the youngest patients (OR = 7.9, 95% CI = 1.9-32.4, p = 0.004). Few differential diagnoses were identified in the study population, and patients older than 30 years of age had malaria less often than the youngest patients (OR = 0.3, 95% CI = 0.08-0.9 and OR = 0.09, 95% CI = 0.02-0.4).

CONCLUSION

This study supports previous reports of over-diagnosis and treatment of malaria in endemic areas. The results suggest that differential diagnoses are important, especially in adults with febrile illnesses to ensure the correct diagnosis and treatment. Further studies are needed to explore the findings and to develop strategies to improve the management of malaria and its differential diagnoses.

A new, clinically oriented, unifying and simple placental classification system

OBJECTIVE

At present there is no internationally accepted, clinically easy understandable, comprehensive morphological placental classification. This hampers international benchmarking and comparisons, and clinical research.

STUDY DESIGN

Internationally published criteria on morphological placental pathology were collected, standardized and focused into a comprehensive diagnosis category system. The idea was to create a clinically relevant placental pathology scheme related to major pathological processes. A system of nine main diagnostic categories (normal placenta included) was constructed. Pathologists and obstetricians discussed the mutual understanding of the wording in the reporting. The previously published diagnostic criteria were merged, structured and standardized. Through an interobserver correlation study on 315 placentas from intrauterine deaths and 31 controls (placentas from live births) the microscopic criteria in this classification system were tested on user-friendliness and reproducibility.

RESULTS

The clinical feedback has been very positive, focusing on the understandability and usefulness in patient follow-up. The interobserver agreement in the microscopic correlation study was in general good. The differences in agreement mainly reflected the degree of preciseness of the microscopic criteria, exemplified by excellent correlation in diagnosing acute chorioamnionitis. Maternal and fetal circulatory disorders need grading criteria and studies are needed to get more insight and clinical correlations of villitis and maturation disorders.

CONCLUSION

The clinically oriented, unifying and simple placental pathology classification system may work as a platform for standardization and international benchmarking. Further research is needed to define diagnostic criteria in staging and grading of some main diagnostic categories.

Effects of serum-free storage on morphology, phenotype, and viability of ex vivo cultured human conjunctival epithelium

The use of amniotic membrane (AM) represents one of the major developments in ocular surface reconstruction. However, in a study on patients with primary pterygium, transplantation of AM with ex vivo expanded human conjunctival epithelial cells (HCjE) promoted earlier epithelialization than AM alone. We previously showed that cultured human limbal epithelial cells maintain their morphology, phenotype, and viability for one week when stored at 23°C. The current study investigates the feasibility of storing HCjE in HEPES-MEM and Optisol-GS at 23°C for 4 and 7 days, respectively. The five experimental groups were analyzed by light microscopy, immunohistochemistry, transmission electron microscopy, and a viability assay. The ultrastructural integrity of cultured HCjE was well preserved following 4 days of storage, however, 7 days of storage resulted in some loss of cell-cell contacts and epithelial detachment from the amniotic membrane. The number of microvilli in cultured HCjE not subjected to storage was 2.03±0.38 microvilli/μm. In comparison, after 4 and 7 days of HEPES-MEM storage this number was 1.69±0.54 microvilli/μm; P=0.98 and 0.89±1.0 microvilli/μm; P=0.28, respectively. After Optisol-GS storage for 4 and 7 days, the mean number of microvilli was 1.07±1.0 microvilli/μm; P=0.47 and 0.07±0.07 microvilli/μm; P=0.03, respectively. The number of cell layers in cultured HCjE not subjected to storage was 4.4±0.3 cell layers, as opposed to 4.0±0.9 cell layers; P=0.89 after 4 days of HEPES-MEM storage and 2.8±0.6 cell layers; P=0.01 after 7 days of storage in HEPES-MEM. The number of cell layers after 4 and 7 days of storage in Optisol-GS was 3.7±0.2 cell layers; P=0.46 and 3.4±0.4 cell layers; P=0.18, respectively. The expression of markers for undifferentiated cells (ΔNp63α, ABCG2 and p63), proliferating cells (Ki67 and PCNA), goblet cells (Ck7 and MUC5AC), stratified squamous epithelial cells (Ck4), and apoptotic cells (caspase-3) in cultured HCjE appeared to be unchanged after 4 and 7 days of HEPES-MEM and Optisol-GS storage. The percentage of viable cells in cultured HCjE not subjected to storage (91.4%±3.2%) was sustained after 4 and 7 days of storage in HEPES-MEM (94.1%±4.5%; P=0.99 and 85.1%±13.7%; P=0.87, respectively) as well as after 4 and 7 days of storage in Optisol-GS (87.7%±15.2%; P=0.97 and 79.8%±15.7%; P=0.48, respectively). We conclude that cultured HCjE may be stored for at least 4 days in serum-free conditions at 23°C while maintaining the phenotype and viability. HEPES-MEM appears to be comparable to Optisol-GS for serum-free storage with preservation of the ultrastructure for at least 4 days.

Acute atherosis in decidual tissue: not associated with systemic oxidative stress in preeclampsia

The aim of this study was to explore a possible association between the presence of decidual acute atherosis, maternal hyperlipidaemia and oxidative stress in the maternal circulation in preeclamptic and uneventful pregnancies. Decidual tissue was harvested by a vacuum suction technique following delivery of the baby and placenta in 102 caesarean deliveries. Maternal plasma lipid profile and concentration of 8-isoprostane, a marker of oxidative stress, was analysed. Acute atherosis was present in 42% of the preeclamptic patients with identified spiral arteries. CD68 positive foam cells were found in the spiral artery walls in 14% of the normal pregnancies. We have previously demonstrated an elevated plasma level of 8-isoprostane in the preeclampsia group, as compared to the uneventful pregnancy group (218 vs. 354 pg/mL, p=0.02). Presence of acute atherosis was, however, not associated with an elevated level of oxidative stress in the maternal circulation, measured as 8-isoprostane. In conclusion, the presence of decidual vascular changes in the form of acute atherosis is not necessarily paralleled by hyperlipidaemia or augmented oxidative stress in the maternal systemic circulation. This study adds to the notion of preeclampsia being a multifactorial disease with a variety of clinical forms.

Clinical prognostic factors in 1277 patients with neuroblastoma: results of The European Neuroblastoma Study Group 'Survey' 1982-1992

In 1982 the European Neuroblastoma Study Group (ENSG) established a prospective registry for patients with newly diagnosed neuroblastoma ('The ENSG Survey'). Clinical information was collected primarily to: (a) establish an ENSG database; and (b) investigate prognostic factors in neuroblastoma. This paper summarises the results of the survey. By 1992, 1277 patients with a median age of 26 months (range: 0-289 months), gender ratio of 1.19 M:F had been registered from 30 centres. The median follow-up of survivors is 9.7 years (range: 1-14 years). Overall 5-year survival (S) is 45% (95% CI 42-48%), and event-free survival (EFS) is 43% (95% CI 40-45%). For both survival and EFS the key established prognostic factors, stage and age, are highly significant (P<0.001). In particular, patients under 1 year of age at diagnosis, whatever the disease stage, had a more favourable prognosis than older patients; stage 2 (EFS 93% (95% (CI 85-97) versus 76% (95% CI 67-86), P=0.02), stage 3 (EFS 91% (95% CI 82-96) versus 52% (95% CI 44-60), P<0.001) and stage 4 (EFS 59% (95% CI 48-69) versus 16% (95% CI 13-19), P<0.001). Multivariate analysis established that the anatomical location of the primary tumour (i.e. abdominal versus other sites) and primary tumour volume also conferred a statistically significant difference. In stage 4 disease the 20% of patients without demonstrable bone marrow involvement had a more favourable prognosis than those with infiltrated marrow (EFS 36% (95% CI 13-19) versus 16% (95% CI 29-45), P<0.001). Urine catecholamine metabolite levels (raised versus normal), histology (ganglioneuroblastoma versus neuroblastoma) and gender had no significant effect on outcome after stage and age were accounted for. 5-year survival following first relapse is only 5.6% (95% CI 2.8-8.4). This ENSG Survey provides secure data for future comparisons with new prognostic factors and treatment programmes.

Sibs with anencephaly, anophthalmia, clefts, omphalocele, and polydactyly: hydrolethalus or acrocallosal syndrome?

Major characteristics of the acrocallosal syndrome include severe mental retardation, agenesis or hypoplasia of the corpus callosum, and polydactyly of fingers and toes. In the past few years, anencephaly has also been noted, together with other midline defects. We report on a nonconsanguineous, Norwegian couple with a history of two pregnancies with a male and a female fetus, respectively, with anencephaly, median cleft lip and palate, omphalocele, and preaxial polydactyly, suggesting the diagnosis of the acrocallosal syndrome. Both fetuses also lacked eyes and nose, a finding not previously reported in the acrocallosal syndrome. Microphthalmia has been reported in the hydrolethalus syndrome, which may be caused by mutations in the same gene as the acrocallosal syndrome. The present report adds support to the hypothesis that the acrocallosal and hydrolethalus syndromes may be allelic conditions. The family history is consistent with autosomal recessive inheritance.

Deterioration in performance in obtaining bone marrow trephine biopsy cores from children. European Neuroblastoma Study Group

AIM

To complete an audit of bone marrow trephine biopsy adequacy in children

MATERIAL

605 specimens from children with neuroblastoma submitted by 25 centres were reviewed centrally. This reassessment ran between January 1995 and August 1998.

RESULTS

25% of specimens (95% confidence interval (CI) 21% to 29%) were inadequate compared with 17% (95% CI 14% to 20%) in a previous study. Variation between individual centres' performance remains high (5-54% of specimens inadequate). Had five centres performed as well as previously, the inadequate biopsy rate would have been unchanged from that found in the previous study. There was no important improvement in any centre's performance. Earlier suggestions about change in practice have had no discernible impact on centres' ability to obtain adequate bone marrow trephine biopsies from children.

CONCLUSIONS

The responsibility for improving the rate of adequate biopsies lies with individual centres. Reporting pathologists might help by making even more positive attempts to influence operators within their own centres.

The International Neuroblastoma Pathology Classification (the Shimada system)

BACKGROUND

The International Neuroblastoma Pathology Committee, which is comprised of six member pathologists, was convened with the objective of proposing a prognostically significant and biologically relevant classification based on morphologic features of neuroblastic tumors (NTs) (i.e., neuroblastoma, ganglioneuroblastoma, and ganglioneuroma).

METHODS

A total of 227 cases were reviewed. Consensus diagnoses from morphologic features (criteria described separately) based on five of six or six of six agreements by the reviewer pathologists were used for prognostic analysis. Prognostic effects of morphology, both individual and in combination, taken in conjunction with age (Shimada classification, histologic grade, and risk group), were analyzed.

RESULTS

Approximately 99% of cases (224 of 227) had consensus diagnoses for categorization: neuroblastoma (Schwannian stroma-poor), 190 cases; ganglioneuroblastoma, intermixed (Schwannian stroma-rich), 5 cases; ganglioneuroma (Schwannian stroma-dominant) maturing, 1 case; ganglioneuroblastoma, nodular (composite Schwannian stroma-rich/stroma-dominant and stroma-poor), 19 cases; and NT-unclassifiable, 9 cases. For the NTs, subtype (93% consensus: undifferentiated, 6 cases; poorly differentiated, 155 cases; and differentiated, 15 cases), mitosis-karyorrhexis index (90% consensus: low, 94 cases; intermediate, 40 cases; and high, 37 cases), mitotic rate (75% consensus: low, 89 cases; high, 50 cases; and not determined, 4 cases), and calcification (100% consensus: yes, 110 cases and no, 80 cases) were recorded. Statistical analysis demonstrated that the Shimada classification system (90% consensus; 3-year event free survival: 85% for the group with favorable histology and 41% for the group with unfavorable histology; P = 0.31 x 10(-9)) had a significantly stronger prognostic effect than individual features and other combinations.

CONCLUSIONS

The International Neuroblastoma Pathology Classification, a system based on a framework of the Shimada classification with minor modifications, is proposed for international use in assessing NTs.

Terminology and morphologic criteria of neuroblastic tumors: recommendations by the International Neuroblastoma Pathology Committee

BACKGROUND

As part of the international cooperative effort to develop a complete set of International Neuroblastoma Risk Groups, the International Neuroblastoma Pathology Committee (INPC) initiated activities in 1994 to devise a morphologic classification of neuroblastic tumors (NTs; neuroblastoma, ganglioneuroblastoma, and ganglioneuroma).

METHODS

Six member pathologists (H.S., I.M.A., L.P.D., J.H., V.V.J., and B.R.) discussed and defined morphologically based classifications (Shimada classification; risk group and modified risk group proposed by Joshi et al.) on the basis of a review of 227 cases, using various pathologic characteristics of the NTs. The classification-grading system was evaluated for prognostic significance and biologic relevance.

RESULTS

The INPC has adopted a prognostic system modeled on one proposed by Shimada et al. It is an age-linked classification dependent on the differentiation grade of the neuroblasts, their cellular turnover index, and the presence or absence of Schwannian stromal development. Based on morphologic criteria defined in this article, NTs were classified into four categories and their subtypes: 1) neuroblastoma (Schwannian stroma-poor), undifferentiated, poorly differentiated, and differentiating; 2) ganglioneuroblastoma, intermixed (Schwannian stroma-rich); 3) ganglioneuroma (Schwannian stroma-dominant), maturing and mature; and 4) ganglioneuroblastoma, nodular (composite Schwannian stroma-richlstroma-dominant and stroma-poor). Specific features, such as the mitosis-karyorrhexis index, the mitotic rate, and calcification, were also included to allow the prognostic significance of the classification to be tested. Recommendations are made regarding the surgical materials to use for an optimal pathobiologic assessment and the practical handling of samples.

CONCLUSIONS

The current article covers the essentials and important points regarding the histopathologic evaluation of NTs. Using the morphologic criteria described herein, the INPC is proposing the International Neuroblastoma Pathology Classification. It is reported in a companion article in this issue (Cancer 1999;86:363-71).

Lipoblastoma: MRI appearances of a rare paediatric soft tissue tumour

Lipoblastoma is a rare, benign soft-tissue tumour derived from embryonic fat. Four patients with tumours located in the upper limb are reported, with special reference to imaging techniques and histology. Radical surgical excision is essential to prevent local recurrence and exact imaging techniques are thus crucial. MRI appears to be a reliable preoperative investigation and is the recommended radiological examination. In a child under 3 months of age, images showing a predominantly fatty but inhomogeneous soft-tissue mass are suggestive of lipoblastoma.

Soft tissue response to polytetrafluoroethylene and silicone rubber in humans: morphological and immunohistochemical observations

The objective of this study was by morphological and immunohistochemical means to investigate the cellular tissue response to the alloplastic materials polytetrafluoroethylene (PTFE polymer), and soft and hard silicone rubber over time. In seven healthy volunteers implants made of Proplast-Teflon, and soft and hard silicone were inserted subcutaneously in unloaded areas in the iliac crest region. After 1, 2, 4, 12, and 26 weeks, respectively, the implants with surrounding soft tissue were removed en bloc for histological and immunohistochemical examination using a panel of antibodies to various leukocyte markers. The tissue reaction to the various alloplastic materials varied greatly with the focus on macrophage and giant cell reactions and eventual formation of a peri-implant fibrous capsule. The most extensive changes developed next to porous Proplast, both with respect to degree of changes and endurance of tissue reaction. Less intense reactions were seen, in decreasing order, to soft silicone, Teflon, and hard silicone. The study gave no clues to a toxic, allergic, or traditional immunological pathogenesis of the tissue reaction induced by the test materials.

[Lipoblastoma. A rare, benign tumor in children]

Lipoblastoma is a rare, benign tumour of embryonal fat seen almost exclusively in infancy and early childhood. It occurs mostly in the extremities, but it is also seen in other parts of the body. The tumour may grow rapidly, and the fact that lipoblastomas show immature fat cells could lead to the wrong diagnosis of liposarcoma. Complete surgical excision appears to be the treatment of choice. A correct, preoperative diagnosis is possible in most cases. Two cases of lipoblastoma of the upper limb and one case in the scapular region are reported.

Bone marrow trephine biopsy in infants. European Neuroblastoma Study Group

Central review of bone marrow trephine biopsies obtained between January 1990 and July 1996 from 282 children with neuroblastoma showed that 18% of cores from older children and an unacceptably high 36% from infants were inadequate (p = 0.0002). Centres should choose their operators for this invasive investigation of infants with more care in order to reduce the failure rate.

Female genital schistosomiasis (FGS): relationship between gynecological and histopathological findings

Schistosomiasis of the lower female reproductive tract manifests itself in a broad spectrum of clinical features. However, clinical and histopathological findings have never been studied in a synoptic manner. Based on the assumption that any type of pathology present in the female reproductive tract is the expression of a complex pathophysiological reaction towards eggs sequestered in the genital tissues, we decided to analyze colposcopic and histopathological findings in a comprehensive manner. Thirty-three women in Malawi with urinary and genital schistosomiasis were examined parasitologically and gynecologically. A thorough colposcopic examination with photodocumentation was performed and biopsies were taken from the cervix, the vagina and/or the vulva for histological sectioning and immunohistochemistry. The predominant colposcopic findings were sandy patches on the cervical surface similar to those seen in the bladder and polypous/papillomatous tumors with irregular surface on the vaginal wall and in the vulvar area. The histopathological sections of sandy-patch-like lesions demonstrated only a small cellular reaction around S. haematobium eggs in various stages of disintegration. In contrast, in the case of polyps the histology revealed a more pronounced immunological reaction characterized by a heavy cellular infiltrate. One case of invasive squamous cell carcinoma of the cervix was diagnosed. We conclude that colposcopy is a useful tool in the detection of FGS related pathology in the lower female reproductive tract and that the synoptic assessment of surface and of corresponding histological sections helped to understand the pathophysiology of S. haematobium associated disease in genital tissue.

Diagnosis of female genital schistosomiasis by indirect disease markers: determination of eosinophil cationic protein, neopterin and IgA in vaginal fluid and swab eluates

Based on assumptions about the pathophysiology of egg-related lesions in the lower reproductive tract, putative indirect disease markers were investigated in vaginal fluids from 54 Malawi adolescent girls and women infected with S. haematobium. These women received a careful gynecological examination during which biopsies were taken from the cervix, and, if present, also from suspicious lesions in the vagina and the vulva. If the biopsies, either in wet crushed preparations or in histological sections, contained eggs the patients were considered to have female genital schistosomiasis (FGS; n = 33). The remainder (n = 21) were classified as having urinary schistosomiasis only. Eosinophil cationic protein (ECP), a cytotoxic granule protein of eosinophils, neopterin, a second messenger molecule generated during the activation of macrophages, and IgA as an indicator of local B-cell activation were quantitatively determined in vaginal fluid. To clarify the origin of ECP, this protein was also looked for in histological sections by an immunohistochemical method. In order to explore whether such disease markers can be detected after absorption to a tampon-like material, ECP and IgA were also assessed after elution from a non-porous, polypropylene fibre web impregnated with vaginal fluid. The concentration of ECP in vaginal fluid and the degree of immunohistochemical staining in histological sections were significantly higher in patients with FGS than in women with urinary schistosomiasis only. The amount of ECP detected in histological sections correlated to the number of eggs/mm2 of compressed genital tissue (rho = 0.36, P = 0.02), and the concentration of ECP in vaginal fluid correlated to the concentration of neopterin as well as to that of IgA (rho = 0.52, P = 0.004 and rho = 0.37, P = 0.02, respectively). Median neopterin concentration in vaginal fluid was also higher in the FGS group, but the difference was not statistically significant. ECP could also be detected in eluates from impregnated fibre webs, but the concentration was approximately one power of 10 less than in the original vaginal fluid. These results demonstrate that indicators of immunological mechanisms related to the egg-granuloma might be useful as indirect disease markers for women with FGS if assessed in vaginal washings or swab eluates.

Central review of bone marrow biopsy specimens from patients with neuroblastoma

In order to achieve some uniformity in histological detection of bone marrow infiltration by neuroblastoma and to provide a measure of variation in histological opinions, sections from 712 evaluable trephine biopsy cores from children in a European Neuroblastoma Study Group (ENSG) study were reviewed centrally. Biopsy specimens were graded as tumour positive or negative. Discordance between local and central review opinions was found in 5% of specimens. Only five of 165 children at presentation and nine of 256 re-staging procedures in 126 children, affecting one child each, had their diagnosis upgraded to positive. In six re-staging procedures, affecting one child each, the diagnosis was downgraded. The low discordance rate is encouraging and substantially less important than previously documented difficulties in obtaining adequate specimens.

High levels of Lp(a) lipoprotein in a family with cases of severe pre-eclampsia

We report a family with two cases of severe pre-eclampsia/eclampsia in which very high levels of Lp(a) lipoprotein were found. The serum level of Lp(a) lipoprotein is genetically determined and the Lp(a) apolipoprotein has a close homology to plasminogen. Very high levels of Lp(a) lipoprotein might interfere with the fibrinolytic/thrombolytic process in man. A previous report suggested that a high maternal serum Lp(a) lipoprotein level can cause fetal growth retardation, and it is proposed that very high levels might lead to increased deposition of fibrin in the uterine spiral arteries in pregnancy, which is central in the pathogenesis of pre-eclampsia. If confirmed, a very high Lp(a) lipoprotein level could be one risk factor for pre-eclampsia that is genetically determined.

Role of ploidy, chromosome 1p, and Schwann cells in the maturation of neuroblastoma

BACKGROUND

Neuroblastoma is a heterogeneous disease, with manifestations ranging from spontaneous regression to lethal spread. Sometimes the tumor spontaneously differentiates toward a benign ganglioneuroma (maturing neuroblastoma). The prognosis is frequently related to ploidy, deletions in the short arm of chromosome 1, and amplifications of the N-myc oncogene. Maturing neuroblastomas consist of both neuronal cells and Schwann cells. We investigated the genetic composition of both cell types in maturing neuroblastomas, to determine the relation between genetic abnormalities and maturation.

METHODS

We studied 20 maturing and mature neuroblastomas by in situ hybridization to count the chromosomes and evaluate possible deletions in the short arm of chromosome 1 in neuronal and Schwann cells. The DNA content of the cells was measured by flow cytometry.

RESULTS

Neuroblastic and ganglionic cells showed aberrations in the number of chromosomes. In situ hybridization and flow cytometry demonstrated near-trip-loidy in 18 of 19 tumors and pentaploidy in the remaining tumor. The Schwann cells in all 20 neuroblastomas contained normal numbers of chromosomes. In 18 tumors studied, there were no chromosome 1 deletions in either type of cell.

CONCLUSIONS

The Schwann cells in maturing neuroblastomas differ genetically from the neuronal cells. The normal number of chromosomes in Schwann cells and the abnormal number in neuroblastic ganglionic cells suggests that Schwann cells are a reactive population of normal cells that invade the neuroblastoma. Near-trip-loidy of neuroblastoma cells and intact chromosome 1 are presumably genetic prerequisites for spontaneous organoid maturation, because we found no diploidy or chromosome 1 depletions in the neuronal cells of spontaneously maturing neuroblastomas.

Adequacy of bone marrow trephine biopsy specimens in children

AIMS

To evaluate success in obtaining adequate bone marrow trephine biopsy cores from children.

METHODS

Sections of trephine biopsy cores submitted by 25 centres from children with neuroblastoma over a five year period were reviewed centrally. In cores containing no tumour adequacy was defined as 0.5 cm of well preserved bone marrow after processing. Occasional smaller cores containing obvious tumour were also considered adequate.

RESULTS

Of 822 biopsy specimens, 139 (17%) were inadequate. In 13 centres submitting at least 20 cores failure rates ranged from 2.6 to 50%. There was no improvement over the five years of the study. There was no practically important correlation between the numbers of cores submitted and success in obtaining adequate specimens. Although a lower rate of inadequate biopsy specimens was found when haematologists rather than paediatricians (13 v 29%) were the predominant operators this should not be overinterpreted, not least because of the potentially confounding association between haematologist operators and larger numbers of biopsy specimens, and because the arbitrary subdivision of centres according to operator specialty was crude. The skill of individual operators could not be assessed.

CONCLUSIONS

Many operators do not obtain adequate bone marrow biopsy specimens from children. Improvement is necessary because this is an invasive investigation, often performed under general anaesthesia. Reporting pathologists are well placed to influence practice by pointing out inadequacies in the specimen and suggesting retraining or even a change in operator. Improvement would almost certainly occur if this investigation was restricted to locally recognised successful operators, whatever their specialty. Most centres should review their practice and devise strategies to improve their ability to obtain adequate cores.

Morphologic and immunohistochemical observation of explanted Proplast-Teflon temporomandibular joint interpositional implants

PURPOSE

The objective of this study was to investigate the cellular tissue response to temporomandibular joint (TMJ) Proplast-Teflon disc material by morphologic and immunohistochemical means.

PATIENTS AND METHODS

Twelve patients who had been subjected to TMJ discectomy combined with insertion of a Proplast-Teflon interpositional implant (PTIPI) were recalled for removal of the alloplastic disc. The time elapsed between the Proplast-Teflon disc implantation and its removal varied between 13 and 71 months (mean, 54.6 +/- 5.8 [SEM]) The implants and periimplant tissues were examined by light microscopy and immunohistochemically using a panel of monoclonal antibodies reactive with different subclasses of leukocytes. The sections were immunostained using the alkaline phosphatase-antialkaline phosphatase (APAAP) technique.

RESULTS

Fibrosis and a massive foreign body giant cell reaction were seen inside the heavily disrupted alloplastic implants and in the periimplant tissues. CD68-positive monocyte-derived cells dominated the reactive infiltrate in the implants and surrounding tissue. The CD68-positive cells also were partly positive for lysozyme. The lymphocytic infiltration contained no B cells.

CONCLUSIONS

This study of the PTIPI-induced tissue reaction gave no indication of a toxic or an immunologic pathogenesis. Mechanical stress seems important in the fragmentation of the implant and induction of the foreign body reaction. It is not yet known if this fragmentation is the major contributing factor.

High Lp(a) lipoprotein level in maternal serum may interfere with placental circulation and cause fetal growth retardation

We report on a woman with an Lp(a) lipoprotein level above the 99th centile of the population distribution of concentrations, who at the age of 43 had had deep vein thrombosis causing a pulmonary embolus and whose brother, who also had a very high level, had suffered a cerebral infarction at the age of 43. She had given birth to three children, all with very low birth weight, one of whom died when 3 months old. The placentas had been small and ischemic. The concurrence of a very high Lp(a) lipoprotein level, familial thromboembolic disease and recurrent placental ischemia with delivery of children with low birth weight suggests the possibility that a very high Lp(a) lipoprotein concentration may predispose to placental insufficiency, presumably arising from pathological changes in maternal uterine vessels in the placental bed. If confirmed, a very high Lp(a) lipoprotein level may be a factor to consider in women who have repeated pregnancies with placental insufficiency and who give birth to children with low birth weight.

Initial interactions of platelets and plasma proteins in flowing non-anticoagulated human blood with the artificial surfaces Dacron and PTFE

The purpose of the present study was to investigate and to compare the interactions of platelets and proteins in flowing non-anticoagulated human blood with the biomaterials polyethylene-terephthalate (Dacron) and polytetrafluoroethylene (PTFE, Teflon). The respective biomaterials were positioned in a parallel-plate perfusion chamber, and exposed to flowing blood for 5 min at wall shear rates characteristic for veins (100/s), medium sized (650/s) and moderately stenosed arteries (2,600/s). Blood-material interactions were morphologically quantified as platelet-surface adhesion, thrombus volume and fibrin deposition. Platelet adhesion to Dacron was highest at the lowest shear rate (13%) and decreased with increasing shear (4% at 2600/s). In contrast, platelet adhesion to PTFE was shear rate independent (17-19%), and significantly higher than the adhesion to Dacron at 2600/s (P < 0.05). A hallmark of the platelets adherent to PTFE and Dacron was the large percentage of platelets not spread out on the surface. This indicates that both materials were poor platelet activators, even though immunostaining demonstrated the adsorption of the platelet adhesive proteins von Willebrand factor and fibronectin. Adsorption of fibrinogen was also prevailing on both materials. Virtually no thrombi formed on Dacron, while a few small platelet thrombi were observed on PTFE. Less than 1% of the Dacron and PTFE surfaces were covered by fibrin, irrespective of the shear rate. Thus, Dacron and PTFE interact differently with flowing non-anticoagulated human blood, and Dacron is apparently the least thrombogenic material.

Cavernous hemangioma of the middle ear

A case of an accidentally discovered, nonsymptomatic cavernous angioma of the middle ear in a 29-year-old white male Caucasian is presented together with a review of the relevant literature. The lesion is documented with computer tomography, light microscopy, and immunohistochemistry.

Faecal calprotectin: a novel test for the diagnosis of colorectal cancer?

Calprotectin, a prominent cytosol protein in neutrophil granulocytes, was present in increased concentrations in stools from 50 of 53 patients with colorectal cancer, 32 of 40 patients with colorectal polyps, and all of 18 patients with gastric cancer. After radical surgery, faecal calprotectin levels reverted to the normal range in all but one patient with colorectal cancer. Calprotectin determinations are simplified by the stability of this protein in stools. Reliable estimates can be obtained in samples of only 5 g. On the basis of data from the literature, the test for calprotectin seems better than that for occult blood for the detection of gastrointestinal neoplasms.

[Cholesterol embolization after intravenous streptokinase therapy in acute myocardial infarction]

The cholesterol embolization syndrome occurs in patients with extensive atherosclerotic disease as a consequence of the showering of cholesterol-rich material from ulcerated atheromatous plaques into the arterial circulation. Cholesterol embolization has been described after angiographic procedures, vascular surgery or anticoagulation therapy and may cause manifestations from multiple organ systems. Only recently, this syndrome has been reported following intravenous thrombolytic treatment for myocardial infarction. We describe one patient who developed cholesterol embolization syndrome with extensive peripheral manifestations after intravenous streptokinase treatment for myocardial infarction. He developed livedo reticularis, with multiple symmetrical skin necrosis and ulcerations below the umbilical region. Repeated histology from ulcerations failed to demonstrate cholesterol crystals in thromboses, only revealing ischemic changes and lack of vasculitis. The patient died of a new myocardial infarction six months after the streptokinase treatment. The abdominal aorta below the renal arteries was covered by extensive atheromatous masses, with partly ulcerated intima.

The use of post-embedding immunoelectron microscopy in the diagnosis of glomerular diseases. Comparison of immunoelectron microscopic and immunofluorescence studies

Fifty renal biopsies were studied by immunoelectron microscopy after embedding in a partly hydrophilic polyacrylic resin (LR White). Immunofluorescence studies were carried out on frozen sections of parallel tissue samples. Polyacrylic embedding gave good preservation of the renal ultrastructure and precise localization of immunoglobulin and C3c antibodies within glomerular electron-dense deposits. Non-specific staining of plasma proteins within vascular lumina could easily be detected. There was good correlation between immunoelectron and immunofluorescence microscopy. Immunoelectron microscopy is a very sensitive method, which can detect small amounts of antigen. More cases were, however, positive by immunofluorescence than by immunoelectron microscopy. This discrepancy may be explained by difference in sample size, and by difference in resolution of morphological details (electron microscopy versus fluorescence microscopy).

[Chronic hepatitis C. Experience with 50 patients]

We studied 50 patients (36 males and 14 females) with chronic hepatitis C who were admitted consecutively to our medical department during the period 1987-91. Eight patients (16%) had had a blood transfusion, 17 (34%) had used intravenous drugs and 25 (50%) were "sporadic cases" with no identifiable risk factor except that at least five had been tattooed. Most of the patients had moderate symptoms, including tiredness and asthenia. Few were jaundiced. A percutaneous liver biopsy was performed in 27 patients and showed chronic persistent hepatitis in 12 of them, chronic active hepatitis in six and cirrhosis in nine. Three patients with cirrhosis died; one from hepatoma, one from an endstage cirrhosis with bleeding and coma hepaticum, and one from septicaemia.

Respiratory tract viruses in otosclerotic lesions. An immunohistochemical study

A series of viral antigens, including adenovirus, influenza A and B, parainfluenza types 1 and 3, measles, mumps, respiratory syncytial (RSV) and Epstein Barr (EBV) viruses was studied in a prospective series of stapes specimens from 24 consecutive patients operated on for otosclerosis. The stapes specimens were processed for light microscopy and immunohistochemistry. With the exception of one case of positive specific reactivity for anti-RSV antibody in one multinuclear osteoclastic cell, no specific reactivity was seen in the specimens. This was the case both in active (n = 8) and inactive (n = 16) otosclerotic lesions. The possibility of unspecific staining reactions is discussed.

Immunohistochemistry on needle biopsies of childhood malignancies

Ultrasound-guided percutaneous needle biopsy proved to be a reliable and safe method to obtain material for histopathological and immunohistochemical diagnosis prior to treatment in childhood malignancies. A principal tumour identification could be obtained by a combined morphological and phenotypic examination of 38 small-sized tumour biopsy specimens using a fairly limited panel of immunological reagents, including antibodies to leucocyte common antigen (CD 45), certain B- and T-cell markers, various intermediate filaments (cytokeratin, desmin and vimentin), and neuroblastoma cells (UJ 167.11, A2B5, and UJ 13A; the latter recognizes NCAM). Five undifferentiated neuroblastomas were all positive with the neuroblastoma antibodies but negative for the other markers, including vimentin. The negative reactivity for desmin and vimentin was the major immunohistochemical distinction between neuroblastomas and rhabdomyosarcomas. In addition, limited reactivity with the neuroblastoma antibodies was seen in blastematous parts of Wilms' tumour, duct-like structures in a hepatoblastoma, and in tumour cells in a few undifferentiated myelo- and lympho-proliferative lesions. This study shows the importance of a combined evaluation of morphology and the pattern of immunoreactivity employing multiple markers.

Rapid supplementary fixation in frozen sections: microwave versus conventional fixation. A double-blind comparative study

The preservation of morphological details in frozen sections subjected to microwave-assisted fixation was compared with that in frozen sections subjected to snap fixation with either formalin/ethanol or ethanol alone. Especially nuclear details were better preserved after short microwave fixation. Ethanol alone gave the poorest results, with loss of nuclear details in the majority of the cases. In this study there was no significant difference between the morphological results obtained with a cheap domestic oven and that with a specialized microwave processor. Microwave-assisted fixation in frozen sections is a simple, rapid method. It is recommended for use in routine laboratories.