Impaired T-cell regulation of B-cell growth in Helicobacter pylori--related gastric low-grade MALT lymphoma.

BACKGROUND & AIMS: Neoplastic B cells of the Helicobacter pylori-related low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma are responsive to T helper cells and sensitive to withdrawal of H. pylori-induced T-cell help. METHODS: The clonal progeny of T cells from the gastric mucosa of 5 patients with MALT lymphoma was compared with that of T-cell clones obtained from 5 H. pylori-infected patients with chronic gastritis. RESULTS: T-cell clones were assessed for specificity to H. pylori, cytokine profile, help for B-cell proliferation, and perforin- or Fas-mediated cytotoxic regulation of B-cell growth. Twenty-eight of 165 CD4(+) gastric clones from MALT lymphoma and 33 of 178 CD4(+) clones from chronic gastritis recognized H. pylori antigens. Cytokine production was similar in the 2 series of clones. All MALT lymphoma-derived clones dose-dependently increased their B-cell help, whereas clones from chronic gastritis lost helper activity at T-to-B-cell ratios greater than 1 because of concomitant cytolytic killing of B cells. T-cell clones from MALT lymphoma had both reduced perforin-mediated cytotoxicity and poor ability to induce Fas-mediated apoptosis. These defects were limited to gastric T cells. CONCLUSIONS: H. pylori-induced T cell-dependent B-cell activation and deficient cytotoxic control of B-cell growth may link H. pylori infection, local T-cell response, and genesis of low-grade gastric MALT lymphoma.     

Surgical treatment and desensitization therapy of giant papillary allergic conjunctivitis.

We found that three cases of giant papillary conjunctivitis responded well to local specific desensitization therapy and transplantation of the conjunctiva with saphenous vein tissue.     

Role of Vincristine in Immunochemotherapy of Leukemia in Mouse or Human Models

Synergistic antitumor effects between Vincristine (VCR) and allograft responses. have been found in mice bearing allogeneic retrovirus-induced leukemia. In this model VCR depressed weakly allograft reactivity if given before but not after antigen administration. In a parallel human tumor model in vitro using HTLV-1 induced MT-2 leukemia, additive but not synergistic immuno-chemotherapeutic effects were obtained with allogeneic mononuclear cells (MNC) combined with VCR at 0.1 but not at 1 mμg/ml. In this case natural immunity (NI) rather than antigen-dependent immunity (ADI) was involved in the combined effets of VCR + MNC. In the in vitro model pretreatment of effector cells with 1 or 0.1 mμg/ml of VCR depressed natural cell-mediated cytotoxicity (NCMC). However when the drug was added to the effector + target cells during the 4 h cytotoxicity assay, 1 but not 0.1 mμg/ml of the drug was capable of depressing NCMC function. These results would provide valuable information for developing in vitro immuno-chemotherapy studies in human tumor systems, including those characterized by the presence of tumor-associated oncogenic retroviruses, capable of depressing both NI and ADI functions.     

Relative influence of different disulphate disaccharide clusters on the HCII-mediated inhibition of thrombin by dermatan sulphates of different origins

Besides the major monosulphated disaccharide sequences (IdoA-GalNAc4SO₃), dermatan sulphates (DS) contain the oversulphated sequences (IdoA2SO₃-GalNAc4SO₃) and (IdoA-GalNAc4,6SO₃), the concentration of which is correlated with the HCII-mediated inhibition of thrombin by DS. The effect of the chemical removal of the sulphate groups on the HCII-mediated activity was studied. The base-catalyzed sulphate group displacement from IdoA2SO₃ residues, leading to formation of the epoxyde aGulA, is a 1st order reaction. When the content of sequences (IdoA-GalNAc4,6SO₃) is higher than that of sequences (IdoA2SO₃-GalNAc4SO₃), removal of the sulphate groups from Ido2SO₃ reduces the HCII activity less than when the latter sequences prevail. (IdoA-GalNAc4,6SO₃) cooperates with (IdoA2SO₃-GalNAc4SO₃) in the activation of the HCII. Also the removal of 6-SO₃ groups from GalNAc4,6SO₃, in absence of IdoA2SO₃-GalNAc4SO₃, considerably reduces the activity. A low molecular mass natural fraction rich in IdoA2SO₃ as well as glucuronic acid, having higher electrophoretic mobility than the higher molecular mass DS which contains less glucuronic acid, is remarkably active.     

The cerebral correlates of subliminal emotions: an electroencephalographic study with emotional hybrid faces

In a high‐resolution electroencephalographic study, participants evaluated the friendliness level of upright and inverted ‘hybrid faces’, i.e. facial photos containing a subliminal emotional core in the low spatial frequencies (< 6 cycles/image), superimposed on a neutral expression in the rest of the spatial frequencies. Upright happy and angry faces were judged as more friendly or less friendly than neutral faces, respectively. We observed the time course of cerebral correlates of these stimuli with event‐related potentials (ERPs), confirming that hybrid faces elicited the posterior emotion‐related and face‐related components (P1, N170 and P2), previously shown to be engaged by non‐subliminal emotional stimuli. In addition, these components were stronger in the right hemisphere and were both enhanced and delayed by face inversion. A frontal positivity (210–300 ms) was stronger for emotional than for neutral faces, and for upright than for inverted faces. Hence, hybrid faces represent an original approach in the study of subliminal emotions, which appears promising for investigating their electrophysiological correlates.     

Atrial fibrillation following chemotherapy for stage IIIE diffuse large B-cell gastric lymphoma in a patient with myotonic dystrophy (Steinert’s disease)

The authors describe the unusual association between diffuse B-cell gastric lymphoma and myotonic dystrophy, the most common form of adult muscular dystrophy, and sudden atrial fibrillation following one cycle of doxorubicin-based chemotherapy in the same patient. Atrial fibrillation or other cardiac arrhythmias are unusual complications in patients treated with chemotherapy. The cardiac toxicity intrinsically associated with the aggressive chemotherapy employed could function as a triggering factor for the arrhythmia in the predisposed myocardium of this patient.     

Whipple's disease. Description of a case and survey of the literature

A case of Whipple's disease (WD) personally observed is described. A 28-year-old male was admitted to hospital for evaluation of weakness, intermittent fever and weight loss arisen since a month. On clinical investigation, he complained of vomit and diarrhea since three months. He had neither familial and personal past history of gastrointestinal diseases, nor any other important diseases. He denied use of drugs. Physical examination was negative. Laboratory findings showed anemia, low blood lymphocytes, low serum iron and total iron binding capacity, low total serum protein and low serum albumin and high level of ESR. Stool were negative for parasites and occult blood. Cultures of blood and urine were negative. Stool fat assay was > 7 g/24 h and D-xylose test showed a two-hour serum concentration < 25 mg/dl. Abdominal TC showed lumbo-aortic and mesenteric enlarged lymph nodes. An upper video endoscopy showed a duodenal lymphangectasia. Histological examination showed villar atrophy with massive infiltration of large PAS-positive diastase-resistant foamy cells. Ziehl-Nielsen staining was negative. WD was diagnosed and patient underwent therapy based on cotrimoxazole. This report emphasizes the difficulty to diagnose WD correctly, because of its rareness and clinical polymorphism. Recently, studies have identified a bacillus, Tropheryma whippelii, associated with WD, so that, in the next future, the diagnosis of WD will be faster and more accurate. Finally, it is important to administer antibiotics which can cross the blood brain barrier for at least one year, in order to prevent neurological relapse, often lethal.     

Interlayer and Intralayer Excitons in AlN/WS2 Heterostructure

The study of intra and interlayer excitons in 2D semiconducting vdW heterostructures is a very hot topic not only from a fundamental but also an applicative point of view. Due to their strong light–matter interaction, Transition Metal Dichalcogenides (TMD) and group-III nitrides are particularly attractive in the field of opto-electronic applications such as photo-catalytic and photo-voltaic ultra-thin and flexible devices. Using first-principles ground and excited-state simulations, we investigate here the electronic and excitonic properties of a representative nitride/TMD heterobilayer, the AlN/WS2. We demonstrate that the band alignment is of type I, and low energy intralayer excitons are similar to those of a pristine WS2 monolayer. Further, we disentangle the role of strain and AlN dielectric screening on the electronic and optical gaps. These results, although they do not favor the possible use of AlN/WS2 in photo-catalysis, as envisaged in the previous literature, can boost the recently started experimental studies of 2D hexagonal aluminum nitride as a good low screening substrate for TMD-based electronic and opto-electronic devices. Importantly, our work shows how the inclusion of both spin-orbit and many-body interactions is compulsory for the correct prediction of the electronic and optical properties of TMD/nitride heterobilayers.