Whole-exome sequencing in osteosarcoma reveals important heterogeneity of genetic alterations.

BACKGROUND: Whole-genome sequencing studies have recently shown that osteosarcomas (OSs) display high rates of structural variation, i.e. they contain many somatic mutations and copy number alterations. TP53 and RB1 show recurrent somatic alterations in concordant studies, suggesting that they could be key players in bone oncogenesis. PATIENTS AND METHODS: we carried out whole-genome sequencing of DNA from seven high-grade OS samples matched with normal tissue from the same patients. RESULTS: We confirmed the presence of genetic alterations of the TP53 (including novel unreported mutations) and RB1 genes. Most interestingly, we identified a total of 84 point mutations and 4 deletions related to 82 different genes in OS samples, of which only 15 have been previously reported. Interestingly, the number of mutated genes (ranging from 4 to 8) was lower in TP53mut cases compared with TP53wt cases (ranging from 14 to 45). This was also true for the mutated RB1 case. We also observed that a dedifferentiated OS harboring MDM2 amplification did not carry any other mutations. CONCLUSION: This study suggests that bone oncogenesis driven by TP53 or RB1 mutations occurs on a background of relative genetic stability and that the dedifferentiated OS subtype represents a clinico-pathological entity with distinct oncogenic mechanisms and thus requires different therapeutic management.

Fine structure of the rectum in cockroaches (Dictyoptera): general organization and intercellular junctions.

The organization of the rectal pads is described in cockroaches belonging to the Groups Blattoidea (Periplaneta americana, Blatta orientalis) and Blaberoidea (Supella supellectillu, Blaberus craniifer). In the Blattoidea, each pad is composed of two layers (principal and basal cells) and is surrounded by very narrow junctional cells supporting the sclerotized cuticle of the pad frame; basally, the junctional cells abut on to the basal cells. In the Blaberoidea, the basal cell layer is discontinuous, the basal cells being interspersed between extensions of the junctional cells beneath the pad. The ultrastructural features of each cell type is described, with special reference to the intercellular junctions, which exhibit unusual complexity. Four types of junction are recognized: desmosomes (belt and spot desmosomes), gap junctions, septate junctions and scalariform (ladder-like) junctions. The last are usually closely associated with mitochondria, forming mitochondrial-scalariform junction complexes (MS). The distribution of these junctions is examined in relation to the partitioning of extracellular spaces, and to the problem of fluid transport.

The organization and isolating function of insect rectal sheath cells: a freeze-fracture study.

In termites and roaches the well-defined rectal papillae each comprise a layer of columnar principal cells specialized for active transport and a layer of basal cells. The whole cell group is entirely surrounded by several series of flattened 'sheath cells' (formerly termed 'junctional cells') which abut onto the basal components of the papilla. The sheath cells secrete a specialized sclerified cuticle which forms the framework of the papilla. Their regularly pleated apical membrane is closely apposed to the cuticle and contains parallel and closely spaced rows of intramembranous particles. at this level, no subcuticular space is present and hence the space associated with the apical surface of the principal cells is defined as an isolated compartment. Typical septate junctions are present between the sheath and basal cells; however those linking adjacent sheath cells are structurally unusual: they extend to the basal surface rather than being restricted to the apical zone, are frequently interrupted and in replicas are represented by relatively short and irregularly oriented particle rows. Moreover, lateral sheath cell contacts display two further peculiarities: absence of an apical desmosomal ring and paucity of gap junctions. Structural observations suggest that the sheath cells isolate the principal cells from communication with the hemolymph, consequently enhancing their efficiency in water and ionic regulation. Comparable cells have been described in a number of insects, but the 'isolation' system presents varying degrees of complexity, for which an evolutionary scheme is proposed.

Septate junctions in insects: comparison between intercellular and intramembranous structures.

Septate junctions have been studied in the hind-gut of Periplaneta americana, Incisitermes schwartzi and Thermobia domestica. The topographical disposition of intercellular septa revealed by lanthanum impregnation corresponds well with that of particle rows seen in freeze fracture preparations. However, there is no precise correspondence between the undulations of septa and the disposition of particles within a single row. The spacing of particles is variable and generally less than that of the undulation periodicity of septa. On the other hand, the disposition of septa, and of the rows of particles that correspond to them, appears to be variable: sometimes rectilinear and in close parallel, these may curve or form series of 'finger-print' loops. Moreover, the septa are evidently not deployed as continuous ribbons around the cell since intrruptions are freuqently observed. In addition to their mechanical role in intercellular cohesion, septate junctions apparently ensure a more or less complete closure of the intercellular space (i.e. provide a permeability barrier) and thus play a role comparable with that of tight junctions in epithelia of vertebrates.

Decreased skin response to intradermal histamine in cancer patients.

The skin response to intradermal injections of serial dilutions of histamine was studied in 68 cancer patients and 29 noncancer, nonallergic subjects. In cancer patients with primary tumor with or without metastasis, incidence and size of wheals and flare were markedly depressed by comparison with control subjects. Pseudopods were rare, and itching was absent. Similar results were observed in patients in which excisions of the primary tumor dated from less than 5 weeks. In contrast, when excision dated from greater than 2 months, skin tests returned to almost normal values. Intermediate values were obtained in patients with metastases alone. This decrease in skin response to histamine was not due to a peripheral neuropathy in cancer patients, since results of electrophysiologic studies were not different in cancer and noncancer patients. The presence of a tumor mimics the effects of general administration of histamine H1 antagonists on the skin response to histamine.

Isolation and characterization of invertebrate smooth septate junctions.

Using modifications of techniques used for the isolation of macula type intercellular junctions (gap junctions and desmosomes) the arthropod smooth septate junction has been isolated from insect midgut tissue. Midguts from cockroaches or mealworms were used and membrane fractions were obtained by sucrose gradient and ultracentrifugation techniques. Preparations with reasonable concentrations of septate junction were obtained and have been studied by thin-section, negative-stain and freeze-fracture electron microscopy. The junctions appeared to be well preserved, although there was evidence that the junction strands were able to slide within the plane of the membrane. Septa were seen to have a cross-striated appearance when viewed after negative staining but their exact structure remained difficult to determine. Polyacrylamide gel electrophoretic studies demonstrated the reproducibility of the isolation procedure and showed that septa may have a 47 000 molecular weight glycoprotein component. Gel electrophoresis also gave some indication of the intramembrane biochemistry of the smooth septate junction, with proteins of 31 000 and 32 000 molecular weight always occurring in the junction fractions. The junctions were, however, very sensitive to both mechanical and chemical treatments, the septa were destroyed by rough homogenization or by treatment with urea at a concentration as low as 1 M. Freeze-fracture of untreated, isolated junctions demonstrated no differences from junctions in intact tissue, while replicas of urea-treated material were more difficult to interpret as the component parts of the junctions became separated once the septa had been destroyed. Gap junctions were also obtained and resisted both mechanical and chemical treatment, which destroyed the septate junctions. Their major protein component appeared to have a molecular weight of 36 000. Attempts to isolate pleated septate junctions (from insects, molluscs and annelids) by the same techniques failed, implying a significant difference in the structures of the two types of septate junction.

Decreased blood histamine levels in patients with solid malignant tumours.

In a one-year follow-up study, 444 blood histamine determinations were performed in 163 patients with solid malignant tumours. Compared with normal subjects, blood histamine levels were significantly lower in patients with unresected primary tumours (30.7 +/- 19.9 ng ml-1), metastases (34.1 +/- 17.1 ng ml-1), or both (24.5 +/- 12.8 ng ml-1). By contrast, after successful tumour resection, histamine blood levels were nearly normal (52.1 +/- 18.4 ng ml-1, versus 59.6 +/- 22.6 in control patients). Stability of the histamine blood levels was associated with stability of the disease. A progressive decrease in histamine blood levels preceded clinical relapse or detection of metastasis. In patients with consecutive histamine blood levels which were less than 15 ng ml-1, survival did not exceed 2 months. In patients with gastrointestinal tumours, blood histamine levels provided information additional to that derived from serum CEA determination. In patients with non-gastrointestinal tumours, the blood histamine level may be of more value than CEA as a marker of disease progression.

Allergic sensitization and clinical reactions to latex, food and pollen in adult patients.

BACKGROUND: Many latex-allergic patients are sensitized to one or more foods. Patients allergic to tree and/or grass pollens are also often sensitized to plant-derived foods. Atopy, defined in most studies as sensitivity to an aeroallergen, is a risk factor for latex allergy. The relative importance of pollen sensitivity, a sign of atopy, as a risk factor for food allergy in latex-allergic patients has not, however, been examined. OBJECTIVE: To investigate the relationship between pollen sensitivity and sensitivity to food in latex-allergic patients. METHODS: Forty-four latex-allergic patients (Groups 1 and 2), 24 of whom were also allergic to tree and/or grass pollen (Group 1) and 25 pollinosis patients who were not allergic to latex (Group 3) were studied. We obtained a history of reactions to food and skin tested them with 12 fresh-frozen fruits. RESULTS: All 12 foods induced a skin test reaction in at least one patient in each of the three Groups. There were, however, twice as many positive skin test reactions to food in patients with pollinosis, whether or not they were allergic to latex, as there were in patients allergic to latex but not to pollen. Latex-allergic patients were most likely to have a positive skin test and a history of a reaction to avocado or banana whereas patients with pollinosis only were most likely to have a positive skin test and a history of a reaction to apple, peach or celery. CONCLUSIONS: These results suggest that concomitant allergy to pollen is an important risk factor in determining which plant-derived foods sensitize latex-allergic patients.

Clinical improvement in advanced cancer disease after treatment combining histamine and H2-antihistaminics (ranitidine or cimetidine).

In a randomized study 31 patients with advanced cancer disease in whom classical anticancer therapy had been abandoned received a daily combination of subcutaneous histamine and oral H2-antihistaminics. In 27 patients, treatment induced a marked clinical improvement as shown by a large rise in performance status (Karnofsky scale). Ten patients were still alive 3-14 months after initiation of treatment. Average survival in the 31 treated patients (172 +/- 113 days) was significantly longer than in 34 non-treated patients with similar advanced cancer (26 +/- 16 days, P less than 0.00001). In six treated patients, the size of liver and lung metastases decreased. Histamine was perfectly tolerated up to 4 mg/day.

Comparison between number of basophils, blood histamine, and histamine release in cancer and noncancer patients.

In cancer patients with primary tumor with or without metastasis or metastasis alone, by comparison with healthy subjects and noncancer patients, the decrease in blood histamine levels is due to a decrease in total basophil number. These basophils have a normal content of histamine (1 to 2 pg per basophil) and are able to release histamine. The percentage of anti IgE-induced histamine release is not significantly different than in noncancer patients. The scarcity of basophils in cancer patients is not due to a leukopenia. Blood histamine levels and total basophil number are normal in patients after successful excision of their primary tumor without metastasis.

Is house dust allergen a possible causal factor for relapses in lipoid nephrosis?

In three cases of minimal change nephrotic syndrome (lipoid nephrosis), an allergen sensitivity to house dust, cat hair and grass pollen was demonstrated by clinical and biological data. An increase in proteinuria after specific allergen contact and a decrease after withdrawal of the allergens, suggested that the cause was allergenic. Such cases demonstrate the necessity of an etiological investigation of particularly the atopic features in lipoid nephrosis. Results of these investigations can lead to specific therapy in selected cases.

[Sensitization by repeated skin tests with candidin and PHA]. / Sensibilisation par tests cutanés itératifs à la candidine et à la PHA.

Intra-dermal skin tests (IST) were applied with candidin (1:100) in 37 subjects and repeated 10 days later. The induration diameter of the second injection (read at 48 h) was greater (p less than 10(-8]. A correlation (r = 0.76, p less than 0.001) appears between the first and second induration diameters. In 17 of these patients (randomly distributed) we measured the absolute number of mononuclear cells bearing receptors of Fc IgG (RFc) before the first and before the second injection. The number of RFc was greater (p less than 0.02) after the second injection. It may be possible that candidin testing increase T suppressor cells. In 20 other subjects, we observed an increase of induration diameter (p less than 0.05) after a second IST of PHA (2 micrograms) applied 15 days after the first injection. Repeated IST with candidin and PHA induce a very high level of booster phenomenon. This fact may be kept in mind when interpreting serial IST in immunodeficiencies.

Basophil sensitisation in idiopathic nephrotic syndrome.

The degranulation of basophils in the presence of a specific allergen (human basophil degranulation test, HBDT) is an index of IgE-dependent cellular response and it was tested in 46 unselected idiopathic nephrotic syndrome (INS) patients with or without atopic manifestations. 28 of the INS patients had "minimal change" nephrotic syndrome (MCNS) and 18 had focal segmental glomerular sclerosis (FSGS). 29 patients with different types of primary glomerulonephritis (GN) and 11 healthy donors acted as controls. The HBDT was positive in 16 (57%) of 28 MCNS and in 14 (77.8%) of 18 FSGS patients. Only 5 (17.2%) of 29 GN and 1 (6%) of 11 blood donors exhibited positive HBDT. House dust was the commonest allergen to which MCNS and FSGS subjects were sensitive, whereas sensitivity to grass pollen, moulds, and animal danders was less common. 8 MCNS and 8 FSGS subjects were sensitive to house dust plus another allergen. 4 MCNS and 1 FSGS patient had fewer than 5/microliters basophils; 4 of these 5 patients were having a relapse of their nephrotic syndrome at the time. The demonstration of enhanced IgE-basophil sensitisation in INS patients suggests than an anaphylactic process plays a part in the pathogenesis of INS.

[Hypereosinophilia in cancer and cirrhosis : utility of total eosinophil count (author's transl)]. / Hyperéosinophilie au cours des cancers et des cirrhoses : intérét du compte absolu des éosinophiles.

A total eosinophil count (TEC) and a white blood cell count (WBCC) were performed simultaneously in 213 patients. Discrepancies were found between TEC and WBCC. WBCC did not allow detection of hypereosinophilia (TEC exceeding 300 eosinophils/microliter) in 45 patients. Patients were classified in three groups : controls (n = 27), benign disease (n = 65), and apparently cured cancer (n = 36). There was no significant difference between total eosinophil counts for these three groups (Wilcoxon non-parametric test). The incidence of hypereosinophilia (TEC exceeding 300) was similar in the three groups (11%, 14% and 6%). Average TEC levels were determined in 20 patients with decompensated hepatic cirrhosis, in 31 patients with active cancer, and in 14 patients with infection. These levels were significantly different from those found in each of the three previous groups. (Wilcoxon test). The incidence of hypereosinophilia (greater than 300/microliter) was significantly higher among patients with cirrhosis (50%) or active cancer (58%). The possible mechanisms of this hypereosinophilia and it's eventual prognostic utility are considered.

[How to define the normal level of serum IgE in adults?]. / Comment définir le taux normal des IgE sériques chez l'adulte?

Variations in the upper limit of normal total serum IgE have been reported: they can range from 150 to 1,000 UI/ml; but the usually accepted upper limit is between 150 and 300 UI/ml. In this study we measured the total serum IgE levels (RIST-Pharmacia) in 69 randomly selected control subjects; 38 had no previous history of atopic or parasitic disease. The normal values observed were 7-460 UI/ml for the whole of the control group (10th-90th percentiles) and 0.5-540 UI/ml for the 38 selected subjects (5th-95th percentiles). Logarithmic conversion is compulsory in order to obtain a gaussian distribution. This enables 80 p. 100 of the control subjects to be grouped within 4-450 UI/ml or 90 p. 100 of the selected subgroup within the range of 1.5-677 UI/ml. As many allergic patients have a normal serum IgE level and a number of non-allergic diseases may be associated with an increased serum IgE level, the diagnostic importance of this investigation is limited. The cost-effectiveness is very low and raises the problem of using this test in everyday practice.

Serum IgE in primary glomerular diseases.

Serum IgE was measured by RIST test in 181 adult subjects, with log transformation. In 24 controls the geometric mean was 109 IU/ml, with an upper limit (geometric mean +/- 2 SD) of 460 IU/ml. 157 cases of glomerulonephritis (GN) classified according to light and immunofluorescence microscopy were studied. Serum IgE was significantly elevated in 39 lipoid nephrosis patients (p less than 0.001, with 21 levels greater than 460 IU/ml), 21 focal and segmental glomerulosclerosis (p less than 0.05, with 8 levels greater than 460 IU/ml) and 42 membranous GN (p less than 0.01, with 10 levels greater than 460 IU/ml). In 27 membrano-proliferative GN and 28 IgA GN, serum IgE was not different from controls with respectively 4 and 3 levels greater than 460 IU/ml. In addition, the lipoid nephrosis IgE geometric mean is 493 IU/ml, which is keeping with the high incidence of atopic troubles. The significance of raised serum IgE was discussed.