Lumican inhibits B16F1 melanoma cell lung metastasis

BACKGROUND

Lumican is a small leucine-rich proteoglycan (SLRP) of the extracellular matrix (ECM) involved in the control of melanoma growth and invasion. The aim of the present study was to analyse the role of lumican in the regulation of the development of lung metastasis.

METHODS

B16F1 melanoma cells stably transfected with lumican expressing plasmid (Lum-B16F1) were injected to syngenic mice. The lung metastasis was compared to mice injected with mock-transfected B16F1 cells (Mock-B16F1). The expression of lumican, cyclin D1, apoptotic markers, vascular endothelium growth factor (VEGF) and Von Willebrand Factor (vWF) within lung metastasis nodules was investigated by immunohistochemistry. In parallel, cells cultured in presence of lumican were assayed for apoptosis and motility.

RESULTS

We observed that the number and the size of lung metastasis nodules were significantly decreased in mice injected with Lum-B16F1 cells in comparison to Mock-B16F1 cells. This was associated with an increase of tumour cell apoptosis within metastasis nodules but the cell proliferation rate remained constant in the two mice groups. In contrast, the VEGF immunostaining and the number of blood vessels within the lung metastasis nodules were decreased in the lumican-expressing tumours. In vitro, a significant decrease of apoptotic markers in wild type B16F1 cells incubated with increasing amounts of lumican core protein was observed. In addition, pseudotubes formation on Matrigel(R) and the migratory capacity of endothelial cells was inhibited by lumican. Altogether, our results indicate that lumican decreases lung metastasis development not only by inducing tumour cell apoptosis but also by inhibiting angiogenesis.

Analysis of structural changes in normal and aneurismal human aortic tissues using FTIR microscopy

Aortic aneurisms are frequently asymptomatic but can induce dramatic complications. The diagnosis is only based on the aortic diameter and not on a structural and compositional basis. In this preliminary study, we propose infrared microspectroscopy to nondestructively probe normal and aneurismal human aortas. Spectra from 19 human ascending aortic biopsies (10 normal and 9 aneurismal) were acquired using infrared microspectroscopy. A 1500 x 150 microm(2) area of each 7-microm thick cryosection was investigated using a 30-microm spatial resolution with a total of about 200 spectra per sample. Spectral differences between normal and aneurismal tissues were mainly located in spectral regions related to proteins, such as elastin and collagen, and proteoglycans (1750-1000 cm(-1)). Tissue heterogeneity and sample classification have been evaluated using hierarchical cluster analysis of individual or mean spectra and their second derivative. Using spectral range related to proteins, 100% of good classification was obtained whereas the proteoglycan spectral range was less discriminant. This in vitro study demonstrates the potential of such technique to differentiate between normal and aneurismal aortas using selected spectral ranges. Future investigations will be focused on these specific spectral regions to determine the role of elastin and collagen in the discrimination of normal and pathological aortas.

Detection of pathological aortic tissues by infrared multispectral imaging and chemometrics

Processing of multispectral images is becoming an important issue, especially in terms of data mining for disease diagnosis. We report here an original image analysis procedure developed in order to compare 42 infrared multispectral images acquired on human ascending aortic healthy and pathological tissues. Each image contained about 2500 infrared absorption spectra, each composed of 1641 variables (wavenumbers). To process this large data set, we have restricted the spectral window used to the 1800-950 cm(-1) spectral range and selected 100 spectra from the aortic media, which is the most altered part of the aortic tissue in aneurysms. Prior to this selection, a spectral quality test was performed to eliminate 'bad' spectra. Our data set was first subjected to a discriminant analysis, which allowed separation of aortic tissues in two groups corresponding respectively to normal and aneurysmal states. Then a K-means analysis, based on 20 groups, allowed reconstruction of infrared images using false-colours and discriminated between pathological and healthy tissues. These results demonstrate the usefulness of such data processing methods for the analysis and comparison of a set of spectral images.

[Dilatation of Virchow-Robin perivascular spaces (types III cerebral lacunae): radio-clinical correlations]

BACKGROUND AND PURPOSE

Virchow-Robin spaces are pia-lined extensions of the subarachnoid space surrounding the path of brain vessels. When enlarged, such dilated perivascular spaces are often seen as foci of cerebrospinal fluid signal on MRI or CT scan. These foci are found in patients with miscellaneous clinical status. It is necessary to determine the radiological significance and clinical associations, if any, in such patients in order to give them the appropriate treatment.

METHODS

We describe the clinical and radiological findings of five patients and review the literature on perivascular Virchow-Robin spaces.

RESULTS

The mechanisms of dilated Virchow-Robin spaces are still not well understood. Such dilated perivascular spaces are found in two locations: typically in the high-convexity white matter of healthy elderly subjects, or surrounding the lenticulostriate vessels as they enter the basal ganglia. On MR images, they may be confused with lacunar infarcts. Most of the patients present with no symptoms: small dilatations located in the high convexity actually represent an anatomic variant, also called "état criblé". Sometimes, giant dilatations, or Poirier's type IIIb "expanding lacunae", found in the basal ganglia and midbrain may result in symptomatic hydrocephalus needing appropriate treatment. For other miscellaneous symptoms as headache, generalized epilepsy, dysmorphy, macrocephaly, there is no reliable correlation with enlarged perivascular spaces seen on MR images.

CONCLUSIONS

The real symptomatic dilated perivascular spaces need appropriate and quick treatment. Most of the other patients present with no symptoms and will remain asymptomatic.

Expression of lumican, a small leucine-rich proteoglycan with antitumour activity, in human malignant melanoma

BACKGROUND

The family of small leucine-rich proteoglycans (SLRPs), which includes decorin, lumican, biglycan and fibromodulin, constitutes an abundant component of the skin extracellular matrix. We previously demonstrated that human lumican inhibits melanoma growth and progression in a mouse experimental model, by regulating cell migration, proliferation and apoptosis.

AIM

The aim of this study was to investigate the expression of lumican and decorin in human malignant melanoma and adjacent peritumoral tissue, to understand better their role in the control of growth and invasion of human melanoma.

METHODS

Expression of both proteoglycans was studied by immunohistochemistry using specific antibodies in 34 malignant melanomas, 12 Hutchinson's melanotic freckles and 4 cutaneous metastatic melanomas.

RESULTS

We showed that lumican and decorin are located in the dermis and in the peritumoral stroma of malignant melanoma, but are not found in melanoma cells or dense tumour tissue. In the healthy dermis, distant from the tumour, the increasing ratio of lumican to decorin was inversely correlated with the proliferation of the tumour cells (P = 0.035). The comparison of the level of expression of lumican protein in superficial vs. nodular subtypes of malignant melanomas showed a decrease of lumican but not decorin in the peritumoral stroma of nodular subtypes. In the peritumoral stroma, the level of expression of lumican but not decorin decreased significantly (P = 0.016) with increasing Clark levels. In addition, immunocytochemical and reverse transcription PCR analyses of malignant melanoma cell lines (A-375, HT-144) and of MRC-5 and dermal fibroblasts from healthy donors in vitro confirmed that dermal fibroblasts are responsible for lumican and decorin synthesis in skin. CONCLUSIONS. Lumican may regulate vertical progression of human malignant melanoma, but further study is necessary to clarify the antitumour mechanism and the downstream signal transduction pathways involved.

Vibrational spectroscopy studies of formalin-fixed cervix tissues

Optical histopathology is fast emerging as a potential tool in cancer diagnosis. Fresh tissues in saline are ideal samples for optical histopathology. However, evaluation of suitability of ex vivo handled tissues is necessitated because of severe constraints in sample procurement, handling, and other associated problems with fresh tissues. Among these methods, formalin-fixed samples are shown to be suitable for optical histopathology. However, it is necessary to further evaluate this method from the point of view discriminating tissues with minute biochemical variations. A pilot Raman and Fourier transform infrared (FTIR) microspectroscopic studies of formalin-fixed tissues normal, malignant, and after-2-fractions of radiotherapy from the same malignant cervix subjects were carried out, with an aim to explore the feasibility of discriminating these tissues, especially the tissues after-2-fractions of radiotherapy from other two groups. Raman and FTIR spectra exhibit large differences for normal and malignant tissues and subtle differences are seen between malignant and after-2-fractions of radiotherapy tissues. Spectral data were analyzed by principal component analysis (PCA) and it provided good discrimination of normal and malignant tissues. PCA of data of three tissues, normal, malignant, and 2-fractions after radiotherapy, gave two clusters corresponding to normal and malignant + after-2-fractions of radiotherapy tissues. A second step of PCA was required to achieve discrimination between malignant and after-2-fractions of radiotherapy tissues. Hence, this study not only further supports the use of formalin-fixed tissues in optical histopathology, especially from Raman spectroscopy point of view, it also indicates feasibility of discriminating tissues with minute biochemical differences such as malignant and after-2-fractions of radiotherapy.

[Immunohistochemistry in ophthalmic pathology: applications and limitations]

We evaluate the applications of immunohistochemistry (IHC) in ophthalmic cytology and pathology. The principles of the techniques used in IHC are described. Recent improvements are highlighted, such as the polymeric labeling two-step method, tyramine signal amplification, rabbit monoclonal antibodies, and labeled nanocrystals. The results of the immunohistochemical methods are collected in bacterial and viral diseases and in tumors of the eye and its adnexa, the pathology of which varies greatly. The results in lymphomas, melanomas, and palpebral tumors were more details for practical reasons. There are widespread applications of IHC in ophthalmic pathology, extending from viral ocular and general diseases to the diagnosis of tumors. In some conditions, this technique needs to be associated with molecular biology investigations. Automation helps establish standard protocols, but IHC is a multistep diagnostic method requiring proper selection, fixation, processing, and staining procedures. From a general standpoint, good communication between pathologists and ophthalmologists is the best guarantee of satisfying results.

FTIR and Raman microspectroscopy of normal, benign, and malignant formalin-fixed ovarian tissues

Ovarian cancer is the sixth most common cancer among women worldwide, and mortality rates from this cancer are higher than for other gynecological cancers. This is attributed to a lack of reliable screening methods and the inadequacy of treatment modalities for the advanced stages of the disease. FTIR and Raman spectroscopic studies of formalin-fixed normal, benign, and malignant ovarian tissues have been undertaken in order to investigate and attempt to understand the underlying biochemical changes associated with the disease, and to explore the feasibility of discriminating between these different tissue types. Raman spectra of normal tissues indicate the dominance of proteins and lower contents of DNA and lipids compared to malignant tissues. Among the pathological tissues studied, spectra from benign tissues seem to contain more proteins and less DNA and lipids compared to malignant tissue spectra. FTIR studies corroborate these findings. FTIR and Raman spectra of both normal and benign tissues showed more similarities than those of malignant tissues. Cluster analysis of first-derivative Raman spectra in the 700-1700 cm(-1) range gave two clear groups, one corresponding to malignant and the other to normal+benign tissues. At a lower heterogeneity level, the normal+benign cluster gave three nonoverlapping subclusters, one corresponding to normal and two for benign tissues. Cluster analysis of second-derivative FTIR spectra in the combined spectral regions of 1540-1680 and 1720-1780 cm(-1) resulted into two clear clusters corresponding to malignant and normal+benign tissues. The cluster corresponding to normal+benign tissues produced nonoverlapping subclusters for normal and benign tissues at a lower heterogeneity level. The findings of this study demonstrate the feasibility of Raman and FTIR microspectroscopic discrimination of formalin-fixed normal, benign, and malignant ovarian tissues.

[Ocular melanoma: immunohistochemical evaluation of the potentially predictive markers of prognosis. Preliminary results]

PURPOSE

To study the characteristics of certain biological parameters, many of which have been recently discovered, to assess their possible contribution to the prognosis of ocular melanoma.

MATERIAL

and methods: 25 patients with ocular and orbital melanoma treated at the Reims Regional Hospital since 1993 were included in the retrospective study. The surgical specimens were put in formalin 10%, then in paraffin. Five proteins were analyzed retrospectively: topoisomerase I, topoisomerase IIalpha, ICBP90, Ki67, and P53 on 200 cells per case.

RESULTS

Of the 25 tumors from 14 men and 11 women, 15 were iris and ciliary body melanomas and ten choroidal melanomas. Histopathologic analysis showed 12 spindle-cell-type melanomas, seven epithelioid-cell-type melanomas and six mixed-cell-type melanomas. The immunohistochemical study found a significant difference in distribution between the cellular types for the topoisomerase IIalpha and Ki67 antibodies. Eight patients had metastasis, six of whom died. The metastasis came from three mixed-cell-type melanomas, three epithelioid-cell-type melanomas, and two spindle-cell-type melanomas. On the other hand, six cases of sclera infiltration were discovered among these eight patients.

CONCLUSION

Several prognostic factors seem to be involved in the progression of melanoma: sclera infiltration seems to be essential in our study. Its rate seems to increase with the tumor size and in epithelioid-cell-type melanomas. The correlation between the different immunomarkers and the appearance of metastasis has not yet been verified.

In-vitro analysis of normal and aneurismal human ascending aortic tissues using FT-IR microspectroscopy

FTIR microspectroscopy has shown to be a proven tool in the investigation of many tissue types. We have used this spectroscopic approach to analyse structural differences between normal and aneurismal aortic tissues and also aortas from patients with congenital anomalies like aortic bicuspid valves. Spectral analysis showed important variations in amide I and II regions, related to changes in alpha-helix and beta-sheet secondary structure of proteins that seem to be correlated to structural modifications of collagen and elastin. These proteins are the major constituents of the aortic wall associated to smooth muscular cells. The amide regions have thus been identified as a marker of structural modifications related to these proteins whose modifications can be associated to a given aortic pathological situation. Both univariate (total absorbance image and band ratio) and multivariate (principal components analysis) analyses of the spectral information contained in the infrared images have been performed. Differences between tissues have been identified by these two approaches and allowed to separate each group of aortic tissues. However, with univariate band ratio analysis, the pathological group was found to be composed of samples from aneurismal aortas associated or not with an aortic bicuspid valve. In contrast, PCA was able to separate these two types of aortic pathologies. For other groups, PCA and band ratio analysis can differentiate between normal, aneurismal, and none dilated aortas from patients with a bicuspid aortic valve.

Nano-biocapteurs pour la recherche et les diagnostics des maladies inflammatoires et du cancer

As part of the ongoing search for ways to decrease the mortality of different pathological conditions related to cancer and inflammatory diseases, nanotechnologies currently under evaluation offer potentially attractive tools for innovative methodologies for early diagnosis, new bioimaging techniques and therapeutic strategies. Nano-tools can be employed for various functions, such as the detection of lesions at very early stages of disease development, extremely precise anatomical localization, or evaluation of the efficacy of medications specifically targeted against cells and pathological tissues. We have synthesized homogeneous CdSe/ZnS (core/shell) highly fluorescent nanocrystals (NC) detectable as individual nanoparticules with a routine fluorescent microscope. These NC are at least 10-fold brighter than the best organic fluorophores and at least 1000-fold more stable against photobleaching than AlexaFluor, for example. When conjugated with proteins, DNA or with drugs, NCs may be excited with the light of any wavelength from UV through visible spectral region providing a range of fluorescence colors depending on their diameter. These properties provide excellent perspectives for high through-put multiplexing and long-term tracking of labeled precursors for days or even weeks. We present here NC applications for ultrasensitive detection of p-glycoprotein, cytokeratins, LCA, Ki67, etc. both on the cellular level and in pathological human surgical specimens.

Evaluation of the suitability of ex vivo handled ovarian tissues for optical diagnosis by Raman microspectroscopy

A pilot Raman microspectroscopy study of formalin-fixed, paraffin-embedded, and deparaffinized sections from the same ovarian normal and malignant tissues was carried out. This approach was considered in order to evaluate the suitability of these ex vivo tissue handling procedures in discrimination as well as biochemical characterization. The spectra of formalin-fixed normal and malignant tissues exhibited no contamination due to formalin, which is indicated by the absence of strong formalin peaks; spectral features also show significant differences for normal and malignant tissues. The differences between spectral profiles of deparaffinized normal and malignant tissues are subtle and spectra show few residual sharp peaks of paraffin. Complete dominance of paraffin swamping signals from tissues was observed in the spectra of paraffin-embedded tissues. Principal components analysis (PCA), which was employed for discrimination of tissue type, provided good discrimination for formalin-fixed and paraffin-embedded tissue spectra. PCA of deparaffinized tissues resulted in a poor classification with significant overlap among the clusters. Thus, this study indicates that formalin fixation is the most suitable among the three procedures employed in the study. Significant differences between spectral profiles of normal and malignant formalin-fixed tissues can not only be exploited for discrimination but can also provide information on biochemical characteristics of the tissues. Deparaffinized tissues provide poor discrimination and information on tissue biochemistry is lost. Paraffin-embedded tissues may provide good discrimination, but predominance of paraffin in the spectra could jeopardize biochemical characterization. Prospectively, as a result of the better availability of paraffin-embedded tissues and problems associated with frozen sectioning of formalin-fixed tissues, the results of this study using paraffin-embedded tissues are very encouraging.

[Pindborg tumor: a poorly differentiated form without calcification]

BACKGROUND

Pindborg tumor is a rare benign epithelial calcified odontogenic tumor. Radiological diagnosis is generally suspected because of the presence of calcifications.

CASE REPORT

A 61-year-old man presented a polymorphous Pindborg tumor of the anterior maxillary. The diagnosis was hindered due to the nonspecific radiographic image and the lack of calcification. Pathology provided the positive diagnosis of poorly-differentiated young odontogenic epithelial tumor.

DISCUSSION

Pindborg tumor is a rare lesions usually found in the posterior mandibular bone. Calcification is a characteristic feature. There are two historical forms, a squamous form with very favorable outcome and a clear-cell form with less favorable prognosis.

Micro-Raman spectroscopy for optical pathology of oral squamous cell carcinoma

Micro-Raman spectra of formalin-fixed oral squamous normal and carcinoma tissues, stored at room temperature for 2 months, have been recorded. Spectra were recorded both in the epithelial and subepithelial regions of the tissues. No noticeable spectral contamination due to formalin was observed. Very significant differences between spectra of normal epithelial and malignant epithelial samples were found. No such differences in spectra of subepithelial malignant and subepithelial normal samples could be observed. This study shows that spectra from the epithelial region changes drastically because of malignancy-induced biochemical changes in this region. Major differences between normal and malignant spectra seem to arise from the protein composition, conformational/structural changes, and possible increase in protein content in malignant epithelia. The differences between normal epithelial and subepithelial spectra, as expected, arise mainly from the collagen in subepithelial tissue. Principal component analysis of the combined sets of spectra-epithelial and subepithelial, normal and malignant- showed that very good discrimination can be achieved by Raman microspectroscopy. This study thus validates the suitability of formalin-fixed tissues for optical pathology in oral malignancy.

Lichen sclerosus is frequently present in penile squamous cell carcinomas but is not always associated with oncogenic human papillomavirus

BACKGROUND

Penile squamous cell carcinoma (SCC) may occur on pre-existing lesions of lichen sclerosus (LS). However, the prevalence of histological changes of LS in penile SCC is not well established. Moreover, mucosal oncogenic human papillomaviruses (HPVs) are sometimes detected in penile SCC, but have not been systematically sought in LS-associated penile SCC.

OBJECTIVES

To establish the prevalence of LS histological changes and of mucosal oncogenic HPV in a series of patients with penile SCC.

METHODS

Consecutive cases of histologically proven penile SCC from a single university hospital over a 14-year period were retrospectively selected and reviewed. Histological signs of LS were systematically sought. HPV was detected by polymerase chain reaction (PCR) amplification of DNA from paraffin-embedded skin samples using general primers GP5+/GP6+ (allowing detection of mucosal HPV) and oncogenic type 16-, 18-, 31- and 33-specific primers.

RESULTS

Eighteen cases of penile SCC were found. The mean +/- SD age of patients at diagnosis was 67.3 (14.5 years). In eight of 18 (44%) cases, SCC was associated with histological features of LS. Seventeen skin biopsy specimens of SCC (nine without and eight with LS histology) were subjected to PCR amplification for HPV. Mucosal HPV was detected in six of them (35%). Five of nine SCCs without histological features of LS were positive for mucosal HPV: three with HPV type 16 and two with only general primers. In contrast, all eight SCCs associated with LS were negative for oncogenic HPV types, although one was positive with general primers.

CONCLUSIONS

Penile SCC seems to be frequently associated with LS histological changes. As with vulval SCC, we found that non-LS-associated penile SCC tended to be frequently associated with oncogenic HPV infection, whereas LS-associated penile SCC was not. Larger series are needed to confirm this association.

[Pathology in the diagnosis and treatment of palpebral tumors]

The authors stress the role and place of pathology in the diagnosis and treatment of eyelid tumors. After a brief report on the main histological characteristics of eyelid tumors and their classification, the pathological methods are described, with particular attention paid to the technical aspects of frozen sections in palpebral surgery.

AIM

This study reports the main pathological techniques available for use in eyelid tumor surgery. The advantages of frozen sections are reported from a retrospective study of basal-cell carcinomas of the eyelid.

MATERIAL AND METHODS

All basal-cell carcinomas treated at the Reims Hospital from 1985 to 1999 were retrospectively studied. The pathological aspects are reported. Most of the tumors (155/193) were examined with frozen sections. Recurrences are considered.

CONCLUSION

Pathology in eyelid tumor surgery must be taken into consideration. Frozen section examination may eliminate recurrences and limit healthy tissue taken at resection. This method is a very useful tool in this type of surgery. The benefits of the classic Mohs technique can be completed by a technique that is more precisely adapted to the control of the lateral limits of the excision in reconstructions which are often complex.

[Malignant fibrous histiocytoma of the eyelid]

Fibrous histiocytomas, mostly benign, have often been reported in the orbit, but only four lesions have been described on the eyelids, with only one malignant. The authors present a case of malignant fibrous histiocytoma of the eyelid in a 76-year-old woman with a difficult histological diagnosis. Characteristics of this pathology are explained from data in the literature.

[Factors of recurrence of basal cell carcinomas of the eyelid]

Basal cell carcinomas of the eyelids can recur, although these recurrences are uncommon. In this retrospective study, all basal cell carcinomas treated at Reims Regional Hospital since 1985 were studied to determine the frequency of recurrence and the factors for recurrence.

MATERIAL

and methods: All basal cell carcinomas treated at Reims Regional Hospital since 1985 were studied. A total of more than 200 patients had been operated on for basal cell carcinoma during this period. Those with orbital extension or a location on 2 eyelids were excluded. Epidemiological factors such as sex, age, tumor location, tumor size, and treatment were noted. Recurrences were uncommon, presenting in ten patients. These recurrences were studied in relation to the existing epidemiological data and the treatment provided, particularly the histological results.

DISCUSSION

Basal cell carcinomas located on only 1 eyelid or 1 canthus can usually be treated with one surgical intervention. Extemporaneous histological study can preclude a local recurrence in most cases, but in some cases the condition may recur some years later. Factors favoring recurrence are difficult to determine.

CONCLUSION

The authors report the number of recurrences after surgical treatment of basal cell carcinomas of the eyelids. The recurrences are relatively uncommon when the treatment has been done with extemporaneous histological examination of the resected edges. These recurrences arise particularly in relatively young patients with no other obvious risk factor.

[Laparoscopic diagnosis of stenosing eosinophilic jejuno-ileitis]

INTRODUCTION

Eosinophilic gastroenteritis of unknown origin could be isolated or integrated in idiopathic hypereosinophilic syndrome. Clinical expression is variable since the lesion may affect any area of the gastrointestinal tract and any layer of the wall.

EXEGESIS

A 25-year-old male patient had digestive symptoms such as peritoneal, obstructive and diarrheal signs, associated with blood eosinophilia, giving evidence for eosinophilic jejuno-ileitis. Computer tomography revealed an extensive obstruction of the jejuno-ileum and thickening of the intestinal wall. The diagnosis was obtained using laparoscopy and controlled wedge biopsy, which showed a predominantly external infiltration of the intestinal wall by eosinophils. The disease evolution was favorable with corticosteroid therapy.

CONCLUSION

Worrying and persistent digestive symptomatology, associated with blood eosinophilia, particularly when intestinal wall infiltration is revealed by computer tomography, should lead one to perform a laparoscopy to guide a surgical biopsy of the intestinal wall.

[Hygiene, architecture and autopsy]

The 24(th) August 1998 decree related to technical prescriptions applicable to hospital mortuaries, to be enacted as of September 11(th) 2001, compels hospital administrations and involved personnel to consider architectural concepts of autopsy room. Nevertheless, the technical prescriptions of this decree seem to be inadequate because an autopsy room requires specific functional and technical organization such as adequate flooring, adapted air-conditioning system and plumbing and of course appropriate autopsy tables. Due to imminent enactement of accreditation procedures, it is likely that in the near future, autopsies will only be performed in centres combining scientific competence and sanitary requirements.

Human DNA topoisomerase I inhibitory activities of synthetic polyamines relation to DNA aggregation

DNA aggregation by polyamines has acquired importance as a prerequisite for the cellular uptake of DNA for gene therapy. Intracellular polyamines are constitutive components of mammalian cells and their availability is critical for cell proliferation. Interference of polyamine biosynthesis by synthetic polyamines leads to cytotoxicity. Optimization of the polyamine structural parameters is necessary to control their DNA aggregation, cytotoxic or enzyme inhibitory activities. We designed two series of tetra- and hexamines and compared their human DNA topoisomerase I (top1) inhibitory effects with the DNA aggregation properties. We show that hexamines are more efficient inhibitors of DNA relaxation by top1 than tetramines and that they suppress the top1-mediated DNA cleavage while tetramines do not. The DNA aggregation abilities within two series of polyamines correlate with the length of their central methylene chain. By contrast, the top1 inhibition within two series does not show the same correlation but demonstrates a threshold inhibitory effect on going from the (CH(2))(12) to the (CH(2))(14) central chain. We show further that the structures of DNA aggregates formed by polyamines with the (CH(2))(10-12) or with the (CH(2))(14-16) chains are very different. The first are a fluid cholesteric-type phases, whereas the second are well-structured aggregates similar to columnar liquid crystals with high packing density of DNA duplexes. The structures of polyamines-induced DNA aggregates are proposed to be crucial for top1 catalysis. The structure-function correlation described here may serve as a guide for rational design of polyamines with desired DNA-aggregation or anti-top1 activities.

Detection and localization of a Ca2+-ATPase activity in Toxoplasma gondii

Toxoplasma gondii, the agent causing toxoplasmosis, is an obligate intracellular protozoan parasite. A calcium signal appears to be essential for intracellular transduction during the active process of host cell invasion. We have looked for a Ca2+-transport ATPase in tachyzoites and found Ca2+-ATPase activity (11-22 nmol Pi liberated/mg protein/min) in the tachyzoite membrane fraction. This ATP-dependent activity was stimulated by Ca2+ and Mg2+ ions and by calmodulin, and was inhibited by pump inhibitors (sodium orthovanadate or thapsigargin). We used cytochemistry and X-ray microanalysis of cerium phosphate precipitates and immunolabelling to find the Ca2+, Mg2+-ATPase. It was located mainly in the membrane complex, the conoid, nucleus, secretory organelles (rhoptries, dense granules) and in vesicles with a high calcium concentration. Thus, Toxoplasma gondii possesses Ca2+-pump ATPase (Ca2+, Mg2+-ATPase) as do eukaryotic cells.

Immunohistochemical study of thrombospondin and its receptors alpha root of beta 3 and CD36 in normal thyroid and in thyroid tumours

AIM

To describe the pattern of distribution of thrombospondin (TSP1) and its receptors, alpha root of beta 3 integrin and CD36, in normal human thyroid tissue and to compare their expression in different benign and malignant thyroid conditions.

METHODS

Immunohistochemistry was used to study TSP1 and its receptors in 40 surgical thyroidectomy specimens (normal parenchyma, 7; follicular adenoma, 4; multinodular goitre, 13; papillary carcinoma, 6; follicular carcinoma, 8; anaplastic carcinoma, 2).

RESULTS

In the normal thyroid parenchyma, there was weak expression of TSP1 limited to the vessels with no staining of the extracellular matrix. In goitres, the expression of TSP1 was more pronounced in areas of fibrosis, with staining of alpha root of beta 3 on thyrocytes located in the vicinity. In thyroid adenomas, expression of TSP1 was slightly enhanced compared with normal tissue, located in the basement membrane of vessels. In papillary carcinomas, TSP1 was abundant in the desmoplastic stroma with a cytoplasmic distribution of alpha root of beta 3 integrin in thyrocytes. In follicular carcinomas, TSP1 was less abundant in the extracellular matrix, limited to the vessels of the stroma with a weaker expression of alpha root of beta 3 on thyrocytes than in papillary carcinomas. In anaplastic carcinomas, TSP1 was only present in the numerous capillaries of the stroma, with a marked positivity for alpha root of beta 3 in one case. No immunostaining of thyrocytes is observed with CD36.

CONCLUSIONS

These results suggest the importance of the interaction between alpha root of beta 3 integrin and TSP1 during remodelling of the matrix in fibrous goitres with areas of early sclerosis comparable with wound healing. In papillary carcinomas, the overexpression of TSP1 restricted to the stroma suggests protective effects against tumour progression.

Comparison of benzo[a]pyrene DNA adduct formation in the skin of two strains of mice selected for resistance (DBA/2) or susceptibility (C3H/HeN) to contact dermatitis

Two strains of mice were selected for resistance (DBA/2) or susceptibility (C3H/HeN) to contact dermatitis. Benzo[a]pyrene-DNA adduct formations was compared in the two mouse strains by a postlabeling procedure to determine if there was a significant effect. Results showed that adduct profiles in DBA/2 and C3H/HeN dermis were qualitatively similar. The total binding levels were higher in DBA/2 mice on the d 2 and the d 10. DNA adduct formation has been shown to inversely correlate with skin allergy induction. Data suggest that the expression of the genes responsible for the differences in responsiveness to chemical induced contact dermatitis in mouse may play an important role in benzo[a]pyrene-DNA adduct formation.

[Dermoid cysts. Epidemiology, clinical and anatomo-pathologic aspects, therapeutic management]

We retrospectively analyzed a series of 17 tumors suggestive of dermoid cysts operated on from January 1, 1991, through November 30, 1997. Mean patient age was 3.68 years. The periorbital localization predominated. Two cases of intraorbital localizations required lateral and medial orbitotomy. Surgical treatment was given in all other cases. We observed no complication nor recurrence.

[How to optimize lymph node dissection in colorectal cancers. A technique for simple and efficacious clarification]

Studies relating to the prognosis of colorectal carcinomas insist on the quality of mesocolic examination and on the frequency of metastases in minute lymph nodes. The aim of our study was to evaluate an easy, rapid and new clearance method recently described by Koren et al. Twenty-one surgical specimens for colorectal carcinomas have been investigated. After lymph node examination with the traditional method, the mesocolic fat was immersed in a clearing solution. After 6 hours, lymph nodes stood out as white chalky nodules, and were dissected. By the traditional method 182 lymph nodes were detected and 89 additional lymph nodes after clearing. In one case, the detection of a metastasis in lymph node after clearing allowed to upstage the tumour from Dukes B (N0) to Dukes C (N+). This easy and inexpensive method allows the detection of minute lymph nodes and helps to establish a more accurate staging.

[What is the contribution of aspiration cytology?]

Aspiration cytology of thyroid nodules is essentially designed to determine the benign nature of the nodule in order to avoid purely diagnosis surgery. It is reliable in the diagnosis of anaplastic papillary and medullary carcinomas and most lymphomas, but is more problematical for the diagnosis of the benign or malignant nature of Hürthle cell tumours and certain vesicular tumours, in which cytology reveals a suspicious, doubtful or undetermined appearance. However, whether they are unambiguous or doubtful, fine needle aspiration cytology results help the surgeon to define the therapeutic strategy under the best possible conditions. A therapeutic approach is proposed, based on the formulation of aspiration cytology results into benign, malignant, suspicious and inadequate.

A method for simultaneous quantification of monoclonal antibody Ki-67 and DNA content by flow cytometry. Application to breast carcinomas

OBJECTIVE

To seek a method assessing Ki-67 immunostaining and DNA content by flow cytometry simultaneously.

STUDY DESIGN

The murine monoclonal antibody Ki-67 (Ki) identifies a nuclear protein complex expressed by all nonquiescent tumor cells. Since the antigen detected by Ki is quite labile in most fixation and embedding protocols, a new method for simultaneous quantification of nuclear Ki immunofluorescence and DNA content by flow cytometry was developed. Unfixed, solid tumor cells are permeabilized only with saponin to preserve Ki antigen. The percentage of Ki-positive cell subpopulations calculated by subtraction of the related aspecific fixation histogram gives optimal results more rapidly than by cytogram analysis. Application to breast carcinoma shows the feasibility of the method.

RESULTS

Significant correlations between Ki staining and the S-phase fraction were observed. Mean Ki labelling rates of aneuploid tumors were significantly higher than those of the diploid tumors, and significant differences between histologic types were found.

CONCLUSION

This technique can be considered a fast, sensitive and optimal method to evaluate the proliferative activity of breast carcinomas and possibly of other solid tumors in a department of pathology.

Quantitative immunolocalization of a P29 protein (GRA7), a new antigen of toxoplasma gondii

Ultrastructural localization of a P29 protein of Toxoplasma gondii was examined on thin sections by an immunogold technique using a P29 antigen-specific monoclonal antibody (5-241-178). Immunolocalization of the P29 protein in extracellular tachyzoites demonstrated that this antigen was present in the dense granules. Thus, we have identified this P29 antigen as the seventh protein (GRA7) to be localized to the dense granules of T. gondii. P29 immunolocalization in intracellular tachyzoites demonstrated association of this antigen with the parasite membrane complex, tubular elements of the intravacuolar network, and with the parasitophorous vacuolar membrane. Our immunolabeling data suggest trafficking of the P29 (GRA7) antigen from the dense granule via the intravacuolar network to the parasitophorous vacuolar membrane on invasion of the tachyzoite into the host cell. (J Histochem Cytochem 46:1411-1421, 1998)

[Incidental discovery of asymptomatic Loeffler fibroplastic endocarditis. Report of a case]

The authors report a case of fibroplastic endocarditis discovered during echocardiography in an asymptomatic patient in the context of assessment of systematized electrocardiographic modifications. The diagnosis, strongly suspected on the basis of the cardiac MRI findings, was finally confirmed by endocardial biopsy.

Pyrimethamine-sulfadoxine treatment of congenital toxoplasmosis: follow-up of 78 cases between 1980 and 1997. Reims Toxoplasmosis Group

The purpose of this study was to determine the clinical and immunological outcome of 78 children with congenital toxoplasmosis treated with the pyrimethamine-sulfadoxine combination between 1980 and 1997.

METHODS

Children were divided into 3 groups according to the initial duration of treatment (always including folinic acid, 5 mg/week by mouth), as follows: pyrimethamine (1.25 mg/kg every 15 d) + sulfadoxine (25 mg/kg every 15 d) for 12 months (Group 1, 47 children), or for 24 months, with or without prenatal therapy (respectively, Group 2, 19 children, and Group 3, 12 children).

RESULTS

Chorioretinitis occurred in 23% of these 78 children. Four children had unilateral blindness, 1 had mild epileptic fits and 1 had psychomotor retardation. The lowest rate of sequelae were in Groups 2 and 3. Immunological rebounds, generally without clinical repercussions, occurred frequently (90% of cases on average) during, or more often after therapy, regardless of the treatment duration. Treatment was always well tolerated.

CONCLUSIONS

Our current treatment strategy for congenital toxoplasmosis consists of a 24-month course of pyrimethamine-sulfadoxine (Fansidar) combined with folinic acid (Lederfoline). If the prenatal diagnosis is positive, we also prescribe this treatment to the mother until delivery. This combination offers satisfactory compliance, adequate serum concentrations, and good preventive efficacy.

Evaluation of the monoclonal antibody antithyroperoxidase MoAb47 in the diagnostic decision of cold thyroid nodules by fine-needle aspiration

Fine needle aspiration (FNA) of cold thyroid nodules has become the first line diagnostic decision for electing which patients need surgery. In order to improve FNA accuracy, the monoclonal antithyroperoxidase (TPO) antibody (MoAb47) was tested. A total of 554 patients were included in this study and among them, 208 were referred to surgery. The results of FNA compared to the final histological diagnosis revealed a sensitivity and a specificity of 94 and 55% respectively, while the sensitivity and specificity of TPO immunodetection on the same cases reached 98 and 83% respectively. By combining the two methods, the 3 false-negative of FNA and 60% of suspicious cytology corresponding to histological benign lesions were correctly identified by immunocytochemistry. With better results than FNA alone, TPO immunodetection with MoAb47 represents a useful adjunct to conventional cytology for selecting patients for surgery.

[Anatomo-clinical prognostic factors of papillary carcinoma of the thyroid. Multivariate analysis: report of a series of 52 cases]

A retrospective study about 52 cases of papillary thyroid carcinomas was carried out with emphasis on histopathological features. The mean follow up period was 10 years. The survival curves were estimated using the Kaplan-Meier method and compared using the log rank test. The multivariate analysis was performed using the Cox's regression model. In univariate analysis, age, Tp (histopathological extension of the tumor), histological differentiation, VAN score (Vascular invasion nuclear Atypia tumor Necrosis) of Akslen and the LeuM1 expression were significant prognostic factors. In multivariate analysis, the Tp and histological differentiation were associated with high risks of poor outcome.

[Multiple isolated cutaneous myxomas]

INTRODUCTION

Cutaneous myxomas are rare. They are more often single; when they are multiple, they may be one of the component of the Carney's syndrome.

CASE REPORT

We report a case of multiple and isolated cutaneous myxomas arising at 19 year-old. Diagnosis was confirmed by histologic studies. Examination failed to reveal other cutaneous or visceral features.

DISCUSSION

The multiplicity of cutaneous myxomas is an essential element for diagnosis of Carney's syndrome; other components and notably atrial myxomas can appeared over time. Normal visceral explorations don't eliminated the diagnosis, and follow-up including screening echocardiography must be ensured before concluding, as in our case, as multiple and isolated cutaneous myxomas.