Recombinant human thyrotropin stimulates thyroid angiogenesis in vivo

BACKGROUND

Endogenous TSH and rhTSH stimulate thyroid growth by a direct effect on thyrocytes. Our hypothesis was that rhTSH may also stimulate thyroid angiogenesis.

STUDY DESIGN

A normal human thyroid tissue sample was grafted into the epigastric area of 14 nude mice. Mice were divided in two groups of 7. The first group (treated mice) received rhTSH stimulation (0.014 UI/mouse/day for 3 weeks), while the second group (control mice) had saline. Histological study with special focus on vascular characteristics was performed by image analysis at day 21 for each graft. VEGF immunostaining score, determined by immunohistochemistry, was defined as the percentage of labeled thyrocytes score, plus an intensity score.

RESULTS

Thyroid follicles showed signs of increased colloid re-uptake activity in rhTSH group within a larger surface area than controls (p <0.01). Thyrocytes were taller in the rhTSH group (p <0.01). The diameter of capillary vessels was larger and the microvessels expansion more important in the rhTSH group (p <0.02). Relative capillary area, defined as the ratio between capillary area and follicular area, was also higher in the rhTSH group (p <0.02). VEGF immunostaining score was increased in the rhTSH group (p <0.01).

CONCLUSION

rhTSH stimulates angiogenesis and local VEGF expression in normal human thyroid.

Distinct responses of xenografted gliomas to different alkylating agents are related to histology and genetic alterations

A series of 12 human gliomas was established as xenografts in nude mice and used to evaluate the relationship between histology, genetic parameters, and response to alkylating agents. Eight were high-grade oligodendroglial tumors, and four were glioblastoma. They were characterized for their genetic alterations, including those considered as "early" alterations, namely loss of chromosome 1 +/- loss of chromosome 19q, TP53 mutation, and those considered as "late" alterations, namely loss of chromosome 10, loss of chromosome 9p, EGFR genomic amplification, PTEN mutation, CDKN2A homozygous deletion, and telomerase reactivation. Chemosensitivity of xenografts to four alkylating agents, temozolomide (42 mg/kg, days 1-5, p.o.), 1,3-bis(2-chloroethyl)-1-nitrosourea (5 mg/kg, day 1, i.p.), Ifosfamide (90 mg/kg, days 1-3, i.p.), and carboplatin (66 mg/kg, day 1, i.p.) was tested by administration of drugs to tumor-bearing mice. Although each tumor presented an individual response pattern, glioblastoma had a lower chemosensitivity than oligodendrogliomas, and temozolomide was the most effective drug. Deletion of 1p +/- 19q was associated with higher chemosensitivity, whereas late molecular alterations, particularly EGFR amplification, were associated with chemoresistance. These results suggest that the combined use of histology and molecular markers should eventually be helpful selecting the most appropriate agents for treatment of malignant oligodendrogliomas and astrocytomas.

Correlation between genetic alterations and growth of human malignant glioma xenografted in nude mice

In order to develop preclinical models of malignant astrocytomas and oligodendrogliomas, a series of 54 resected gliomas (37 from oligodendroglial lineage and 17 from astrocytic lineage) were xenografted subcutaneously into nude mice. Molecular alterations commonly observed in gliomas subtypes, including LOH 1p and 1q, LOH 19q, LOH 10p and 10q, LOH 9p, TP53 and PTEN mutations, EGFR amplification, CDKN2A homozygous deletion and telomerase reactivation were systematically screened in the original and xenografted tumours. In all, 23 gliomas grew in nude mice. The most anaplastic tumours were selected as shown by pathological and molecular studies of the original tumour as well as shorter survival in patients whose tumours were successfully grafted. Comparison between the two growth profiles showed that 10q LOH and EGFR amplification gave a tumorigenic advantage. With a few exceptions, the genetic pattern was remarkably stable before and after growth in nude mice. These results suggest that subcutaneous xenografts are useful and reproducible models to analyse the molecular profile of malignant astrocytoma and oligodendroglioma. This represents the first step to improve our understanding of the correlations between molecular alterations and response to standard or experimental therapies.

Efficacy of sulforaphane in eradicating Helicobacter pylori in human gastric xenografts implanted in nude mice

Sulforaphane, an isothiocyanate abundant in the form of its glucosinolate precursor in broccoli sprouts, has shown in vitro activity against Helicobacter pylori. We evaluated the effect of sulforaphane in vivo against this bacterium by using human gastric xenografts in nude mice. H. pylori was completely eradicated in 8 of the 11 sulforaphane-treated grafts. This result suggests that sulforaphane might be beneficial in the treatment of H. pylori-infected individuals.

[Development of human fetal neuroretina grafted into nude mice]

PURPOSE

To determine the role of different ocular tissues in the development of the human fetal neuroretina heterotopically implanted in nude mice.

MATERIAL AND METHODS

Fifty eight eyeballs obtained from legally aborted 6- to 7-week-old embryos or 8- to 10-week-old fetuses were heterotopically implanted in nude mice. Over a period of 1-245 days, all the grafts were removed for light and electron microscopy observations.

RESULTS

All grafts were successful. Twenty six exhibited a normal histological organization of the choriocapillaris, the retinal pigment epithelium, and the neuroretina in the posterior part of the eye. Photoreceptor differentiation was observable approximately 80 days after transplantation and was complete at 166 days. The anterior part of the retina was always dysplasic. Twenty three eyes had a dysplasic neuroretina with folds, rosettes, and necrotized areas. In absence of retinal pigment epithelium, the neuroretina was always dysplasic or absent. Nine eyes were atrophic without any differentiation of the neuroretina.

CONCLUSION

These results demonstrate that the development of a stratified neuroretina requires both rapid revascularization and normal development of retinal pigment epithelium. When these conditions are not met, the neuroretina becomes dysplasic or atrophic or disappears.

Ocular tissue interactions during the development of human fetal neuroretina grafted into nude mice

To determine the roles of different ocular tissues in the development of the human fetal neuroretina, a study ethically and technically impossible in human subjects, human embryonic and fetal retinas were heterotopically implanted into nude mice. Ninety-five eyeballs were obtained from legally aborted 6- to 7-week-old embryos or 8- to 10-week-old fetuses. Ten isolated neuroretinas with vitreous but without pigment epithelium, 20 half-eyeballs and 70 intact eyeballs, of which 12 had a thick layer of periocular tissue, were microsurgically grafted. Five intact eyeballs were used for reference. Over a period of 1-245 days, all of the grafts were removed for light and electron microscopy observations. All of the isolated neuroretinas had disappeared by the second day after transplantation. Grafts of the posterior section of the eyeball contained only some clusters of pigment epithelium, occasionally covered with undifferentiated neuroretinal cells. Grafts of the retrolental section of the eyeball contained small areas of dysplasic neuroretina with folds and rosettes. Grafts of the 70 intact eyeballs were successful, but only 26 showed normal histological organization of the choriocapillaris, the retinal pigment epithelium and the neuroretina in the posterior part of the posterior chamber. Photoreceptor differentiation was evident in these retinas after approximately 80 days of transplantation and was complete after 166 days. Their anterior part was always dysplasic, with occasional ciliary differentiation. Twenty-three grafted eyeballs had a dysplasic neuroretina with folds, rosettes and necrotized areas. Twenty-one were atrophic, 12 of which were the eyeballs grafted with periocular tissue. These results demonstrate the role of the fetal mesenchyme and pigment epithelium in the rapid revascularization, and subsequent survival and tissue organization, of the neuroretina. The stratified development of the neuroretina required a thin mesenchymal environment for revascularization of the graft by human vasculogenesis or neoangiogenesis and a normal retinal pigment epithelium for normal neuroretinal differentiation. When these conditions were not satisfied, the neuroretina disappeared or was dysplasic, partly necrotized or atrophic. This model might prove useful for a number of therapeutic or clinical studies.

Xenografted human whole embryonic and fetal entoblastic organs develop and become functional adult-like micro-organs

BACKGROUND AND AIMS

The aim of this study was to study the morphological and functional development in vivo of whole human embryonic and fetal stomachs, intestines, tracheas, and lungs, which would otherwise be ethically and technically impossible to perform in utero, by microsurgically grafting these organs into nude mice.

MATERIALS AND METHODS

Five hundred fifty-seven human organs obtained from legally aborted embryos and fetuses of 6-10 weeks were microsurgically grafted into nude mice for 1 to 273 days. Following different grafting times, biopsies were taken for optical and electron microscopy, in situ hybridization, and cellular kinetics studies. A catheter was introduced into the human organs in order to collect and analyze secretions.

RESULTS

All of the grafts took successfully. Macroscopic growth was fast during the first 6 to 10 weeks, following which organ size was stable. In situ hybridization studies detected only a minute level of mouse mesenchymal chimerism in the grafts. The different epithelial cells differentiated, became of adult type, and remained normal during the remainder of the grafting periods. The pH of gastric juice from stomachs grafted for 10 to over 90 days dropped from 8.0 +/- 0.1 to 1.58 +/- 0.29 over this time period (P < 0.001), intrinsic factor levels were stable, and pepsin ranged from 6.8 +/- 7.8 to 134 +/- 51 units (P < 0.001).

CONCLUSIONS

These results demonstrate that the development of entoblastic organs from human embryos and fetuses microsurgically grafted into nude mice is similar to that occurring in utero. As such, this method provides a model for the analysis of whole human organs in development and later normal adult-like micro-organs for physiological, therapeutic, and pathological studies.

Morphologic and functional development of whole human fetal stomachs grafted into nude mice

To study in vivo the cellular differentiation and secretion of human developing fetal stomach, ethically and technically impossible to perform in utero, 256 fetal stomachs were xenografted. Human stomachs from 6- to 10-week-old fetuses were grafted for 1-273 days into nude mice. Biopsies for immunohistochemistry, hybridization and electron microscopy were taken and a catheter introduced into the human stomach. Macroscopic growth was fast and cells in S phase were numerous during the first 9 weeks, then the stomach size was stable and the gastric mucosa, of adult type, remained normal. In situ hybridization detected only a minute mouse mesenchymal chimerism in the graft. Chromogranin A, intrinsic factor and H+/K+ adenosine triphosphatase were immunohistolocally detected in epithelial cells 20 days after grafting, gastrin was detected after 30 days and pepsinogen after 60 days. The pH in gastric juice, which was at 8.0 +/- 0.1 from days 10-25, dropped from 4.39 +/- 1.80 at 30 days to 1.58 +/- 0.29 at 90 days. Intrinsic factor was stable and pepsin ranged from 6.8 +/- 7.8 to 134 +/- 51 units at 90 days. The differentiation of the epithelial cells in xenografts was very accelerated in comparison to that in utero.

Increased expression of the vascular endothelial growth factor is a pejorative prognosis marker in papillary thyroid carcinoma

Vascular endothelial growth factor (VEGF) is a potent stimulator of endothelial cell proliferation. It has been implicated in tumor growth of human thyroid carcinomas. Using the VEGF immunohistochemistry staining score, we correlated the level of VEGF expression with the metastatic spread of 19 cases of thyroid papillary carcinoma. The VEGF immunostaining score, ranging from 0-9, was determined as the multiplication of a percentage of labeled thyrocytes score (0, no labeling; 1, <30%; 2, 31--60%; 3, >61% of labeled thyrocytes) and an intensity score (0, no staining; 1, weak; 2, mild; 3, strong staining). The mean score +/- SD was 5.74 +/- 2.59 for all carcinomas. The mean score for metastatic papillary carcinoma was 8.25 +/- 1.13 vs. 3.91 +/- 1.5 for nonmetastatic papillary cancers (P < 0.001). By discriminant analysis, we found a threshold value of 6.0, with a sensitivity of 100% and a specificity of 87.5%. There were no statistical differences between metastatic and nonmetastatic carcinomas when age, tumor size, or thyroglobulin levels were considered. The VEGF immunostaining score seems to be a helpful marker for metastasis spread in differentiated thyroid cancers. An increased production of VEGF could assess an aggressive disease and be the hallmark of a trend to produce metastasis. We propose the VEGF immunostaining score as a marker for the prognosis in differentiated thyroid cancers. A value of 6 or more, should be considered as at high risk for metastasis threat, prompting the physician to institute a tight follow up of the patient.

In vivo potentiation of radiation response by topotecan in human rhabdomyosarcoma xenografted into nude mice

The lack of new highly efficacious drugs for cancer treatment promotes the search for innovative therapeutic modalities. The authors reported the results leading to the definition of parameters needed to demonstrate a possible radiopotentiation by topotecan (TPT) on two representative human rhabdomyosarcomas (RMSs) xenografted into nude mice. Experimental studies of radiopotentiation with different doses of topotecan showed that concomitant association of topotecan and RT for 5 consecutive days provided a synergistic therapeutic effect. Response rates were statistically higher with the radiochemotherapeutic combination (P < 0.001). Efficacy enhancement factors of this combination compared with the sum of the antitumoral activity of these treatments separately administrated were 1.54 and 1.60, respectively, on both rhabdomyosarcomas. Moreover, the efficiency of the combination of radiotherapy at the dose of 20 Gy with topotecan (12.5 mg/kg) was not statistically different from that of radiotherapy at the dose of 40 Gy. According to microscopy results, the analyses performed at different periods after topotecan treatment alone, radiotherapy alone, and their combination seemed to show that tumoral repopulation by malignant cells is as fast as the dose of radiotherapy and/or topotecan is low. Furthermore, lesions observed with the dose of 40 Gy were similar to those obtained with the association of topotecan at the dose of 12.5 mg/kg and radiotherapy at the dose of 20 Gy. In conclusion, all clinical and pathological results are consistent with a radiopotentiation effect of topotecan on the two xenografted human rhabdomyosarcomas and are currently leading to the design of clinical studies.

Acid secretion and response to pentagastrin or omeprazole in human fetal stomach xenografts

BACKGROUND

The dual capacity of stomach tissue to secrete acid and to respond to secretagogues is indicative of the terminal stages of gastric functional maturation. In this study 6- to 10-week-old human fetal stomachs xenografted into nude mice were used to study parietal cells' functional maturation.

METHODS

Thirty-four transplants were microsurgically grafted either inside a pouch created on the nude peritoneum (n = 15) or on the host stomach and esophagus (n = 19). The mucosa of transplanted tissues was analyzed by immunohistochemical techniques to detect gastric cells. Gastric cell secretions were collected before and after pentagastrin or omeprazole treatment.

RESULTS

Parietal, G, and D cells were detected immunohistochemically only after 1 month of grafting. All xenografts actively secreted acid after 1 or 2 months' transplantation at each graft site. Acid secretion was significantly stimulated by intraperitoneally injected pentagastrin (mean pH +/- SD, 3.2 +/- 0.7 vs. 2.0 +/- 0.5; n = 10, P = 0.005) and was dramatically inhibited by intragastrically administered omeprazole (2.3 +/- 0.6 vs. 6.5 +/- 0.7; n = 15, P = 0.0007) after 5 hours.

CONCLUSION

Stomach xenografts were able to develop normally. Parietal cells were physiologically mature with functional proton pumps and active gastrin receptors, as demonstrated after omeprazole and pentagastrin treatment, respectively. Because stomach xenografts matured very rapidly, it is possible that a stomach xenograft model can be used for further studies on the functional maturation of human gastric epithelial cells, as well as the factors that influence this maturation in humans.

[Fragmentation of hydrogel episcleral implants: a series of 4 cases]

A histopathologic study was performed on 4 capsule specimens obtained after surgical removal of hydrogel episcleral implant previously sutured to the scleral surface aiming to reattach the retina. Fragments of hydrogel were found on the inner surface of the capsular fragments, each of them parts of the capsule, which coated the hydrogel implant on the scleral surface. Some fragments were surrounded with a foreign body giant cell granulomatous reaction. Changes in scleral curvature and scleral thinning were consequences of the buckling procedure. The hydrogel fragmentation previously observed in experimental and human specimens gave histologic evidence of degradation of this material after its implantation on the eye surface. This characteristic demonstrates the instability of the material after implantation.

[Histological changes related to scleral buckling for treatment of retinal detachment]

Treatment of retinal detachment frequently uses biocompatible materials to obtain scleral buckling. These materials are not devoid of consequences on surrounding tissues. In 3 eyes enucleated for failure of surgical treatment using scleral buckling materials, the changes prompted by episcleral implants could be observed. The sclera underwent both an inversion of its curvature and a reduction of its thickness under the material, as well as an encapsulation of the material was observed. While a silicone sponge was used in part to encircle one of these eyes, its capsular inner surface was regular and smooth. In contrast, hydrogel implants used in the three eyes showed a peripheral fragmentation prompting in two of them a typical foreign body giant cell granulomatous reaction. Changes in scleral curvature and scleral thinning were observed reflecting the consequences of the buckling procedure. The capsule formation occurred as it does for any nonabsorbable matérial implanted in tissues. Degradation and fragmentation of the hydrogel material suscitated a granuloma in response to fragments. These hydrogel specific changes should be recognized on microscopic examination of slides of either capsule or eyes previously in contact with this implanted material. They attested of the instability of hydrogel after implantation.

Gastric penetration of amoxicillin in a human Helicobacter pylori-infected xenograft model

The delivery of antibiotics into Helicobacter pylori-infected human stomachs is still poorly understood. Human embryonic gastric xenografts in nude mice have recently been proposed as a new model for the study of H. pylori infection. Using this model, we compared the penetration of amoxicillin, after intraperitoneal administration of a dose of 20 mg/kg of body weight, into the gastric mucosae of infected and uninfected xenografts. The concentrations of this drug in serum and superficial gastric mucosae were determined at 20 min and 1 and 3 h after injection. Ten mice with H. pylori-infected grafts (n = 5) or uninfected grafts (n = 5) were studied. Mucosal samples were obtained by cryomicrotomy. The concentrations in serum were similar to those obtained in the serum of humans after oral administration of 1 g of amoxicillin. The mean area under the tissue concentration-versus-time curve from 0 to 3 h obtained for mice with infected grafts was significantly higher than that obtained for the animals with uninfected grafts (P = 0.01). These results suggest that the penetration of amoxicillin into the superficial gastric mucosa may be substantially increased in the case of H. pylori infection. Thus, human xenografts in nude mice represent a new, well-standardized model for investigation of systemic delivery of drugs into H. pylori-infected gastric mucosa.

Assimilation of [57Co]-labeled cobalamin in human fetal gastrointestinal xenografts into nude mice

Cobalamin (Cbl) and its Cbl-binding proteins are present in amniotic fluid. Because amniotic fluid is swallowed by the embryo-fetus, we studied the ability of Cbl to be transported and metabolized across the embryo-fetal digestive tract. Human embryonic stomachs and intestines were transplanted into nude mice. The basal secretion of Cbl-binding proteins was studied by gel filtration of the graft juices. Intrinsic factor (IF) was looked for in gastric mucosa by immunohistochemistry. The uptake of [57Co]-labeled Cbl by the intestinal graft was studied by Schilling tests and HPLC. IF, haptocorrin, and a transcobalamin-like protein were detected in gastric juice, with concentration ranges of 5.0-26.4, 1.9-27.1, and 5.2-12.6 pmol/mL, respectively. The IF [57Co]Cbl complex had a single isoprotein with a pI at 5.6, which was maintained after incubation with neuraminidase. Urine excretion percentages (Schilling tests) ranged from 5.5 to 21.2% and from 0.3 to 1.6% when cyano-[57Co]Cbl-IF or cyano-[57Co]Cbl, respectively, was instilled in intestinal grafts. Chloroquine reduced significantly the percentage of excreted [57Co]Cbl. The [57Co]Cbl was mainly excreted as cyano-[57Co]Cbl in urines, showing a low coenzyme conversion. In conclusion, IF is secreted by the nonstimulated embryonic stomach and lacks sialic acid. Cbl binds to it and is subsequently transported across the xenografted embryo-fetal intestine. This suggests that amniotic fluid may contribute to Cbl delivery to the embryo-fetus.

Vascular endothelial growth factor gene and protein: strong expression in thyroiditis and thyroid carcinoma

Angiogenesis is implicated in several pathological conditions, such as inflammation and tumor growth. Vascular endothelial growth factor (VEGF), also known as vascular permeability factor, is a potent stimulator of endothelial cell proliferation in vitro and in vivo. The present work aimed to compare VEGF expression in human normal thyroid glands, thyroiditis tissue and thyroid carcinomas using immunohistochemistry and in situ hybridization (ISH). Both chronic lymphocytic thyroiditis and differentiated thyroid carcinomas were found to strongly express VEGF mRNA and encode larger amounts of VEGF than normal thyroid tissue as attested by a VEGF immunostaining score. In addition, tumor samples from patients with metastases showed a higher immunostaining score than their non-metastatic counterparts (P<0.05). Carcinomas with the greatest contents of VEGF mRNA and VEGF protein had the most intense mitogenic activity. Special focus on endothelial cells showed intense mitogenic activity in neoplastic tissues in contrast to the total quiescence of endothelial cells in non-tumoral tissues. An intense VEGF production by differentiated thyroid carcinoma, attested either by a higher immunostaining score or a strong VEGF mRNA expression using ISH, could be a promising marker of tumor aggressiveness and may also be useful as a predictor of metastatic potential.

Human embryonic gastric xenografts in nude mice: a new model of Helicobacter pylori infection

In vitro or animal models have been used to investigate the pathogenesis of Helicobacter pylori infection. However, extrapolation to humans of results obtained with these heterologous models remains difficult. We have developed a new model for the study of H. pylori infection that uses human entire embryonic stomachs engrafted in nude mice. At 80 days after implantation, 22 of these xenografts, which exhibited a mature gastric epithelium, were inoculated with 10(7) to 10(8) CFU of either H. pylori LB1, a freshly isolated H. pylori strain (n = 12), or H. pylori ATCC 49503 (n = 10). After 12-week examination, H. pylori LB1 persistently colonized the antrum of all inoculated grafts, as assessed by culture (mucus and mucosa), immunohistochemistry (mucosa), and a rapid urease test (mucus). H. pylori ATCC 49503, either before or after in vivo passage, permitted only a transient 2-week colonization in one of the five inoculated grafts in both groups. Colonization was always associated with an increase of gastric juice pH. A mild neutrophil infiltration of the gastric mucosa was noted solely in infected grafts. Transmission electron microscopy showed adherence of H. pylori organisms to epithelial cell surface. In six animals, intracytoplasmic location of this bacterium was observed in the antrum or the fundus. These results allow us to propose this model as a new ex vivo model for the study of specific H. pylori-gastric cell interactions.

[Isolated invasive sphenoid aspergillosis]

Isolated aspergillosis of the sphenoid sinus is a difficult diagnosis because the often misleading clinical manifestations of this rare disease develop late. We report a case of invasive aspergillosis uniquely involving the sphenoid sinus revealed by clinical features suggesting pseudotumor of the pituitary in an immunocompetent man. A 71-year-old man presented sudden onset palsy of the abductor nerve of the left eye. Neuroimaging suggested a pseudotumor of the pituitary. Sphenoid sinusitis was discovered at surgery. The diagnosis of aspergillosis was provided by the histology examination of the sphenoid mucosa. Despite medical treatment with itraconazol alone then in combination with amphotericine B, the infectious process progressed to the pituitary, the cavernous sinus, the upper orbital fissue and the optic canal. Cure was finally achieved after a second surgical procedure to drain and aerate the sphenoid sinus. Aspergillosis of the sphenoid sinus is usually discovered due to neurological signs such as a cavernous sinus syndrome, pseudotumor of the pituitary or the orbit. Diagnosis is often made intraoperatively or at histology examination. Invasive forms almost always are seen in immunosuppressed subjects. In our case, the patient was immunocompetent and had no past history of sinusitis. The invasive sphenoid aspergillosis invaded bone tissue, the cavernous sinus and the meninges.

Cell and tissue distribution of synthetic oligonucleotides in healthy and tumor-bearing nude mice. An autoradiographic, immunohistological, and direct fluorescence microscopy study

Antisense oligonucleotides have the ability to inhibit individual gene expression in the potential treatment of cancer and viral diseases. However, the way parenterally administered oligonucleotides distribute themselves into healthy tissues or tumors is poorly understood. In this study, the cell and tissue distribution of two modified or unmodified phosphodiester pentadeca-beta-oligonucleotides intravenously administered to healthy or tumor-bearing nude mice was assessed by autoradiography as well as by direct fluorescence and immunoenzymatic histological methods. Resistance of oligonucleotides to degradation by nuclease activity was previously studied in vitro. Using these methods we were able to show the following: 1) within minutes, oligonucleotides permeate all cells and tissues with the exceptions of erythrocytes and intervertebral discs; 2) cell and tissue distribution does not depend on the sequence of the given oligonucleotide; 3) concentration of oligonucleotides is higher within the connective tissue cells than in the interstitial matrix; 4) after uptake, oligomers partition throughout all of the cellular compartments, including at the highest intracellular concentrations in the nuclei; 5) oligonucleotides penetrate easily the tumor cell compartments, oligonucleotide diffusion being unimpeded by the extracellular matrix.

[Comparative study of four commercialized serologic methods for the diagnosis of gastric Helicobacter pylori infection]

OBJECTIVE

Four commercially available enzyme-linked immunosorbent assays (ELISA) were evaluated for serological diagnosis of Helicobacter pylori (H. pylori) infection in 79 untreated patients.

METHODS

Infection has been diagnosed in 40 patients, in whom culture and/or urease test and histopathology from antral biopsies, were positive for H. pylori.

RESULTS

Sensitivity (Se) and specificity (Sp) of these tests, calculated with indeterminate serological results (9 patients) classified as positive (ind +) or negative (ind -), were not statistically different: GAP-test (Bio-Rad), Se = 95% (ind +), 90% (ind -), Sp = 84.6% (ind +), 89.7% (ind -); Pylori-Stat (Biowhittaker), Se = 97.5% (ind + or -), Sp = 71.8% (ind +), 71.9% (ind -); Premier H. pylori (Biomedical Diagnostics), Se = 92.5% (ind +), 90% (ind -), Sp = 84.6% (ind +), 81.2% (ind -); Cobas-Core (Roche), Se = 92.5% (ind + or -), Sp = 76.9% (ind +), 79.5% (ind -). There was a strong correlation between mucosal inflammation and H. pylori status. Discrepancies between infectious status and at least one serology result were observed in 16 patients (11 H. pylori negative and 5 H. pylori positive patients).

CONCLUSION

These 4 tests are of equivalent diagnostic value. Thus, the selection of one of them should take into account cost and practicability.

The role of platelet-derived growth factor production by tumor-associated macrophages in tumor stroma formation in lung cancer

Lung cancer is the most common cause of death by cancer in developed countries. Since a tumor cannot develop without the parallel expansion of a tumor stroma, a better understanding of its formation could lead to new therapeutical approaches. In this respect, since platelet-derived growth-factor (PDGF) is a chemotactic and growth factor for mesenchymal and endothelial cells, lung tumors of patients undergoing surgery for non-small cell lung cancer were evaluated for their replication rate using iododeoxyuridine incorporation, and for the expression of PDGF genes and the presence of PDGF A and B chains and of PDGF receptor alpha and beta subunits. This observation demonstrates that: (a) tumor cells and stroma mesenchymal cells, but not tumor-associated macrophages, display a high replication rate; (b) 1 of 3 tumors are characterized by cancer cells expressing the genes for PDGF A and/or B chains, while 1 of 2 tumors are composed of tumor cells presenting PDGF receptors alpha and beta subunits on their surface, and in only 1 of 6 tumors, tumor cells coexpress PDGF and its receptor; (c) in almost all tumors, tumor-associated macrophages express PDGF A and/or B chain genes; (d) mesenchymal cells, as well as endothelial cells, do not express PDGF A and B chain genes but do express PDGF receptor alpha and beta subunits; and (e) an ongoing active process was suggested in the periphery of the tumor by the simultaneous strong expression of PDGF A and B chain genes by tumor-associated macrophages and the high replication rate of mesenchymal and endothelial cells in the same area. Thus, PDGF is likely to have a limited autocrine role in tumor cell replication but is a potential player, in a paracrine fashion, in tumor stroma development.

Are grafts of parts of human embryos resulting from requested legal abortions on to nude mice licit?

'Nude' mice are mammals which are congenitally incapable (for well-known biological reasons) of rejecting grafts of any tissue from any other species. It is thus possible to transplant human tissues into these animals and to study their survival or growth over long periods (one year or more). For obvious ethical reasons, the study of the development of tissues and organs of human embryos cannot be carried out directly on women during pregnancy. All experimental embryology studies are therefore carried out on other mammals. Requested legal abortions provide tissues and organs from human embryos of four to ten weeks on a daily basis. Can the grafting of parts of human embryos on to 'nude' mice be envisaged for scientific, diagnostic or therapeutic purposes? Can these transplants be left to develop and to be modified experimentally? What regulations need to be established in this new scientific domain? These questions and some initial outlines of answers are presented in this article.

Squamous metaplasia expression of proto-oncogenes and P 53 in lung cancer patients

BACKGROUND

The question of whether bronchial squamous metaplasia is a true preneoplasia is important and demonstrated in animal for several carcinogens. We have now approached this problem in humans and in vivo.

EXPERIMENTAL DESIGN

Squamous metaplasia in the close vicinity of surgically resected lung tumors were evaluated for their mitotic index and screened for proto-oncogenes and P 53 protein expression by immunohistochemistry and/or in situ hybridization.

RESULTS

Among 16 patients, 4 had squamous metaplasia positive for either myc messages and/or for P 53 protein accumulation. In the same patients (3/4), the autologous bronchial tumors were also positive for the same markers. Squamous metaplasia positivity was observed essentially in patients with advanced diseases and only in squamous cell carcinomas. In addition, when evaluated with 5 iodo-2'-deoxyuridine systemic infusion, all patients presented hyperproliferative basal squamous metaplasic cells.

CONCLUSIONS

These results are reminiscent of the typical preneoplastic changes observed in familial colic adenomatosis, where genetic changes accumulate in hyperproliferative cells. They also suggest that bronchial squamous metaplasia could be an authentic preneoplasia in, at least, squamous cell carcinomas.

Host-donor interactions in healing of human split-thickness skin grafts onto nude mice: in situ hybridization, immunohistochemical, and histochemical studies

The behavior of host and donor cell lines in human split-thickness skin grafts onto nude mice was studied by in situ hybridization (ISH) using genomic DNAs as probes, and immunohistochemically with species-specific or cross-species specific antibodies, at different stages ranging from day 3 to more than 1 year following grafting. Changes in the graft vascular and interstitial extracellular matrix were also assessed using species-specific or cross-species specific antibodies to human or murine type I, III, and IV collagens. Finally, transplant reinnervation was investigated using antibodies to various nerve cytoplasmic antigens and the thiocholine method to demonstrate acetylcholinesterase. Using these methods we were able to show the following: (1) the graft epidermis that is not replaced by mouse keratinocytes is progressively colonized by recipient Langerhans cells (LCs); (2) revascularization of the grafts begins soon by inoculation of the graft vessels with the host microcirculatory bed, and mouse endothelial cells growing into preexisting human capillary tubes produce a new basement membrane, prior to the replacement of the original one; (3) within 3-5 days following grafting, mouse fibroblasts migrate into the graft dermis. The density of the human and murine fibroblast populations then progressively increases. Characterization of the interstitial collagens identifies both human and murine type I and III collagens. Production of type III collagens decreases during the progression of fibrogenesis while human type I collagen becomes the predominant matrix protein; (4) transplant reinnervation is deficient, and neurites growing into severed graft nerve trunks were never detected.

[Helicobacter pylori gastritis: a new infectious disease. Reflections from personal experience]

To determine the relationship of microscopic chronic antral gastritis to Helicobacter pylori, 69 consecutive patients were studied. In a prospective longitudinal study, at least 2 successive gastroscopies with antral biopsies were performed (177 investigations on the whole). Sixty six of the 69 patients were treated with various therapeutic regimens i.e. antiulcer drugs and/or antibiotics. The type and intensity of inflammation (as based on whole inflammatory infiltrate density, polymorphonuclear cells presence or absence and IgA and IgM plasma cells counts) were correlated with H. pylori status (Giemsa staining and/or biopsy culture). The presence of the organism (Hp) and the gastritis were significantly correlated (high grade of whole inflammatory infiltrate Hp + ve: 98/109 90 p. cent, Hp-ve: 9/61 15 p. cent, p less than 0.001--presence of neutrophil PMNC Hp + ve: 80/109 73 p. cent, Hp-ve: 1/61 2 p. cent; p less than 0.001--IgA and IgM plasma cells respectively Hp + ve: 7.6 +/- 6.6, 10.6 +/- 7.1, Hp-ve 1.9 +/- 2.9, 4.2 +/- 4.5; p less than 0.005). Clearance and/or eradication of H. pylori after antibiotic treatment were associated with the disappearance of chronic gastritis activity and a statistically significant decrease of whole inflammatory infiltrate density (p less than 0.001) and IgA (p less than 0.005) and IgM (p less than 0.01) plasma cells counts. Mucosal inflammation was unchanged in case of H. pylori persistence and inflammation worsening occurred in case of infection relapse. H. pylori gastric mucosa colonization seemed to be responsible for the antral chronic inflammation associated with its presence. This study documents that antral chronic gastritis is a microbial disease associated with infection by H. pylori, against which there is an inflammatory response characterized by a significant mucosal infiltration with granulocytes and IgA and IgM secreting plasma cells.

[Helicobacter pylori gastritis: a new infectious disease. Reflections from a personal experience]

To determine the relationship of microscopic chronic antral gastritis to Helicobacter pylori, 69 consecutive patients were studied. In a prospective longitudinal study, at least 2 successive gastroscopies with antral biopsies were performed (177 investigations on the whole). Sixty six of the 69 patients were treated with various therapeutic regimens i.e. antiulcer drugs and/or antibiotics. The type and intensity of inflammation (as based on whole inflammatory infiltrate density, polymorphonuclear cells presence or absence and IgA and IgM plasma cells counts) were correlated with H. pylori status (Giemsa staining and/or biopsy culture). The presence of the organism (Hp) and the gastritis were significantly correlated (high grade of whole inflammatory infiltrate Hp + ve: 98/109 90%, Hp-ve: 9/61 15%, p less than 0.001--presence of neutrophil PMNC Hp + ve: 80/109 73%, Hp-ve: 1/61 2%; p less than 0.001--IgA and IgM plasma cells respectively Hp + ve: 7.6 +/- 6.6, 10.6 +/- 7.1, Hp-ve 1.9 +/- 2.9, 4.2 +/- 4.5; p less than 0.005). Clearance and/or eradication of H. pylori after antibiotic treatment were associated with the disappearance of chronic gastritis activity and a statistically significant decrease of whole inflammatory infiltrate density (p less than 0.001) and IgA (p less than 0.005) and IgM (p less than 0.01) plasma cells counts. Mucosal inflammation was unchanged in case of H. pylori persistence and inflammation worsening occurred in case of infection relapse. H. pylori gastric mucosa colonization seemed to be responsible for the antral chronic inflammation associated with its presence.(ABSTRACT TRUNCATED AT 250 WORDS)

Human nerve xenografting in nude mouse: experimental study of graft revascularization

In the nude mouse, the congenital absence of T lymphocytes makes it possible to implant human nerve grafts without rejection or iatrogenic modifications (by immunosuppression) of human and murine tissues. Medial antebrachial cutaneous nerves were harvested from human cadavers 1-18 hours after death. These nerve grafts were implanted using different techniques in nude mice. All the grafts were macroscopically and microscopically revascularized 3 days after implantation. The modifications in time of this vascularization could be studied with precision through the use of repeated biopsies. The absence of human blood group antigens on the neovessel endothelium suggested a murine origin for angiogenesis. In situ DNA hybridizations with human and mouse DNA confirmed this origin. The topography of the revascularization (maximal in the perineurium and endoneurium) and the almost complete absence of human cells other than Schwann cells in the grafts at the peak of angiogenesis (26 days after grafting) suggested that Schwann cells had a determining role in graft vascularization. The irradiation of the nerve grafts with a dose of 30 grays before implantation did not modify significantly their histologic appearance compared to the control group, whereas an irradiation of 60 grays led to massive lesions. The neurotization of murine axons led to chimerical structures of normal histologic appearance, with vascularization similar to that observed in nonneurotized nerves. Through chimerism (human Schwann cells, murine vessels and axons) this model makes it possible to dissociate the respective role of the host and of the nerve graft in angiogenesis and suggests the existence of growth factors produced by the human Schwann cells.

Sublocalisation of the X breakpoint in the translocation (X; 18)(p11.2; q11.2) primary change in synovial sarcomas

A specific translocation between chromosomes X and 18 was identified in synovial sarcomas. From a girl with synovial sarcoma, we isolated two clones with t(X; 18)(p11.2; q11.2) and which had lost the normal X chromosome. Southern blot analysis of DNA from the tumor, the patient and her parents demonstrated that the normal X chromosome, lost in the tumor, was the paternal one. A somatic hybrid cell line was established by fusing tumor cells (after passages on athymic mice) to an HPRT deficient hamster cell line. By cytogenetic, in situ hybridization and molecular analysis, it was found to contain the derivative (X) chromosome in the absence of the der (18) chromosome. To determine the position of the breakpoint on the X chromosome, Southern blots of DNA from this hybrid were hybridized to [32P]-labelled X chromosome probes. DXS146 and DXS255 were retained in the hybrid cell line whereas GAPDP1, the ARAF1 and TIMP proto-oncogenes were not present, indicating that the breakpoint lies proximal to GAPD1, ARAF1 and TIMP and distal to DXS255 and DXS146. Results obtained from other authors are compared. Further studies will be necessary to determine the extent of variation of the breakpoint in different tumors.

Experimental and clinical study of fast absorption cutaneous suture material

Fast Absorption Vicryl was irradiated with gamma rays. The experimental study on 14 mice grafted with human skin showed a constant rupture of the sutures on the 12th day, with the development of a moderate macrophage reaction. Injection of isotonic saline around the suture material did not accelerate the process of resorption. The clinical study with 27 children operated on the limbs showed rupture of the sutures between the 12th and 16th days, without inflammatory reaction, infection or wound dehiscence. Simply wiping the wound with a compress removes the stitches painlessly. This is appreciated by the young subject and his or her family. Since we began to use FAV systematically we have not needed to conduct dressing under anesthesia. The long term results of healing (follow-up: 11.3 months) are similar to those obtained with conventional non-absorbable suture material. The tolerance, the rapid resorption, the comfort of the patient and the cost advantage make FAV the suture material of choice.

Transplantation of human hyperthyroid tissue to the nude mouse. An experimental model

This study analyzes the outcome of human normal and hyperfunctioning thyroid tissue transplanted to the nude mouse. Thyroid fragments from 7 patients with Graves' disease were transplanted to nude mice (nu/nu). Before surgery, the patients had been treated with propranolol and iodine; none had received antithyroid therapy. The transplants were removed on the 12th day following transplantation and were studied by light microscopy and autohistoradiography. At this time, all immunologic disorders found on the operative samples had disappeared, and the tissue had lost its hyperfunctioning characteristics. In contrast, transplants from toxic adenoma remained hyperfunctioning, with elevated serum T3 and T4 levels. Similarly, transplants from normal thyroid tissue remained unchanged, and serum T3 and T4 levels remained within the normal range, as if under the influence of the hypothalamic and pituitary regulation of the mice. These findings emphasize the role of the extrathyroid immunologic environment in the regulation of Graves' disease, whereas toxic adenoma remains autonomous.

Behaviour of thyroid tissue from patients with Graves' disease in nude mice

Thyroid tissue from five patients with hyperthyroidism due to Graves' disease was transplanted into nu/nu mice (2 to 4 mice per thyroid) in order to assess whether the tissues would remain hyperfunctional. Before surgery, the patients received only propranolol and iodine for ten days. Transplants were removed from the mice after 10, 20, 30 or 57 days, and compared to the initial tissue, as well as toxic nodules from two patients and thyroid tissue from two normal subjects grafted similarly. All transplants survived, as proven by histology and autohistoradiography with 131I uptake, while all signs of hyperfunction and dysimmunity disappeared. Conversely, both transplanted toxic nodules remained hyperfunctional. These results indicate that, in spite of the in situ presence of most factors of auto-immune reactions, thyroid tissue from patients with Graves' disease is not autonomous and depends on the extra-thyroid environment.

[Contribution of per- and trans-endoscopic pH measurements to the exploration of the upper digestive tract (author's transl)]

Per- and trans-endoscopic pH measurements in the upper digestive tract have provided new and interesting data. Performed by the authors on a series of 314 patients, they showed that the gastric pH is seldom acid, even in duodenal ulcer, and is always alkaline in gastric ulcer and gastric carcinoma. Gastritis may be divided into two groups, depending on whether the pH is normal or hypoacid (4.5 in the antrum, 2.5 in the fundus). Biopsies demonstrated the presence of intestinal metaplasia and epithelial dysplasia in 57.8% of 83 patients with hypoacid gastritis. The method therefore constitutes a simple and reliable means of determining markers of precancerous lesions.

[Giant lymphoid hyperplasia of mediastinum (Castleman's syndrome). Two cases (author's transl)]

The authors report the cases of two patients with localized lymph node hyperplasia of angio-follicular type. One presents the plasma cell type, biological abnormalities and a shoulder-hand syndrome; the patient recovers after removal surgery. The other, of hyaline vascular type, is asymptomatic.

[Surgical grafting of malignant human melanomas into athymic nu/nu mice : macroscopic and microscopic study]

Tissue from 5 human malignant melanomas was surgically grafted into 39 athymic mice, 20 on lombar muscles covered by their aponevrosis, 13 on the intraperitoneal surface of the abdominal wall, 6 between the dorsal muscles and rib cage. These encapsulated, non-infiltrating, non-destructive tumours were clinically, macroscopically and histologically benign, but cytologically they have a malignant aspect. These were no perceptible visceral, cutaneous or muscular metastases. It would seem that a phenomenon of loosing of invasivness and destruction appeared. However further studies with other tumours and different experimental conditions will be needed to confirm the existence of this phenomenon.

[Grafts of human skin containing nevi or superficial nevocarcinoma onto athymic nu/nu mice: macroscopic and microscopic studies]

17 thin grafts of corpse skin containing neavi, were grafted onto the back of athymic mice. All the grafts took. The naevi were than deeply incised on 3 occasions. No evidence of abnormal healing, of pigment release, or of malignant transformation, appeared. 10 epidermal grafts of superficial malignant melanoma, taken from 4 different patients, took successfully. In 7 of these, superficial ulcerations appeared but were definitively re-epithelialised from the adjacent Mouse skin. 5 and 7 months later, the melanoma are stable, without local extensions, infiltration or apparent metastase. Despite the absence of an inflammatory reaction, these melanoma are paradoxically quiescent in nude Mice.

[Macroscopic and microscopic study of human corpse skin grafting on athymic mice nu/nu]

32 thin grafts (500 to 700 mu) of different human corpse skin set apart during the first 24 hrs after the death have retaken on athymic Mousse whatever the reason of death and the age of the donor. 20 thick grafts have retaken at 30%. These skins preserve the aspects and behaviour of normal human skin but after 1 month they have a heavy melanic hyperpigmentation. These skins preserve their normal histological aspect during the first 3 days, then, when revascularisation is setting in, superficial areas of epidermic mortification, opposite dermal hypovascularised zones, appear. Between the 15th and the 21st day the epidermic alterations disappear and a heavy melanic hyperpigmentation is set up. The revascularisation is certainly the result of the human dermal vessels repermeabilisation. Till the 76th day neither dystrophy, dysplasia nor important inflammatory process exist.