IgM and IgG antibody response in two immunosuppressed patients with Legionnaires' disease: Evidence of reactivation of latent infection

Two patients in whom pneumonia due to Legionella pneumophila developed while they were receiving immunosuppressive therapy had serologic evidence of prior infection with the same serogroup of L. pneumophila two and eight months prior to their clinical pneumonia. This suggests that the pneumonia in these patients may have been due to the reactivation of a latent infection, possibly due to their immunosuppressed state. A new enzyme-linked immunosorbent assay (ELISA) was developed to detect IgG and IgM antibodies to L. pneumophila, and the kinetics of these antibody responses were useful diagnostically.     

Intermediate and High-Grade Gastric Non-Hodgkin's Lymphoma: A Prospective Study of Non-Surgical Treatment with Primary Chemotherapy, with or without Radiotherapy

The role of surgery as initial treatment in gastric lymphoma remains controversial. We have prospectively evaluated a stomach conservation strategy in histologically aggressive gastric lymphoma, using primary adriamycin-containing chemotherapy, followed by involved-field radiotherapy in patients with limited disease. Twenty-six patients (median age 69 years) were entered in this study; 15 had stage I disease, 7 had stage II disease and 4 had stage IV disease. The chemotherapy combinations were CHOP (18 patients) and ProMACE/MOPP (8 patients). Radiotherapy was given to 11 patients. Of the 24 patients evaluated for response, 18 (75%) achieved endoscopically-confirmed complete response and 4 (17%) partial response. During follow-up (median 22 months), none of the complete responders developed recurrent lymphoma. Gastric resection was performed in 1/26 patients who did not respond to primary chemotherapy. There were no cases of perforation, but three patients (12%) developed acute gastro-intestinal bleeding a few days after the onset of chemotherapy, one of whom required a surgical devascularization procedure. There was no treatment-related mortality. These data further support the non-surgical approach in histologically aggressive gastric lymphoma, using primary chemotherapy with or without radiation therapy.     

CIRCULAR DICHROISM SPECTRA OF ISOLATED SOYBEAN AND CHICKPEA TRYPSIN-CHYMOTRYPSIN INHIBITORS

Circular dichroism spectra of trypsin-chymotrypsin inhibitors from soybeans and chickpeas have been determined in acidic, neutral and highly alkaline solutions. Neither protein contains α-helix although a small amount ofβ-structure cannot be excluded. Negative dichroism above 250 nm has been assigned largely to disulfide bonds in both molecules with neither showing evidence for tyrosine residues buried in hydrophobic regions. The spectra of these inhibitors between 230 and 250 nm have been compared with the spectra of a number of structurally related proteins suggesting that previous interpretations of this region may have been incomplete or incorrect.     

Utility of sonographically guided biopsy in metabolically suspected recurrent lymphoma.

OBJECTIVE: The purpose of this study was to determine the diagnostic accuracy of sonographically guided biopsy of [(18)F]fluorodeoxyglucose (FDG)-avid foci on positron emission tomography (PET)/computed tomography (CT) in patients with lymphoma. METHODS: We retrospectively reviewed the medical records of 56 patients with lymphoma (25 male and 31 female; mean age, 48.5 years; range, 22-80 years) who underwent sonographically guided biopsy of hypermetabolic FDG-avid foci precisely localized by PET/CT. Biopsies were performed up to 3 months after PET/CT. The accuracy of core biopsy was calculated and compared with clinical follow-up and histopathologic results of open biopsy. RESULTS: Sixty-six sonographically guided biopsies were performed in the 56 patients. Histopathologic results were conclusive in 53 (80%) of 66. No complications occurred during or after the procedure. The overall sensitivity, specificity, positive predictive value, and accuracy for diagnosis of lymphoma were 100%, 95%, 97%, and 98%, respectively. CONCLUSIONS: Sonographically guided biopsy is a safe and effective means for investigating metabolically active lesions on FDG-PET/CT in patients with known lymphoma.     

Immunomodulatory and protective effects of moxifloxacin against Candida albicans-induced bronchopneumonia in mice injected with cyclophosphamide

In a previous study, moxifloxacin was shown to ameliorate immunosuppression and enhance cytokine production in several tissues, including the lungs of cyclophosphamide-injected mice. We examined here the effects of moxifloxacin on Candida albicans lung infection in cyclophosphamide-injected mice. Mice were injected on day 0 with 250 mg of cyclophosphamide/kg, and on days 1 to 4 they were given moxifloxacin at 22.5 mg/kg/day compared to controls given ceftazidime at 75 mg/kg/day or saline. On day 6, C. albicans (10 7 CFU/mouse) was inoculated intratracheally, and animals were observed for the development of bronchopneumonia, weight loss, mortality, the presence of C. albicans, and lung cytokine production. Histopathology on day 10 postinoculation revealed bronchopneumonia in 50, 67, and 0% of saline-, ceftazidime-, and moxifloxacin-treated mice, respectively (P < 0.05). The mortality rates were 28, 17, and 5%, respectively (P < 0.05), and weight loss occurred at 20, 32, and 0%, respectively (P < 0.05). By day 15, C. albicans was eliminated from all moxifloxacin-treated mice but was still isolated from lung homogenates of 50 to 60% of the saline- and ceftazidime-treated groups. Among the cytokines tested on days 0 to 15, we found an increased production of tumor necrosis factor alpha, KC (functional interleukin-8), and gamma interferon in the lungs of ceftazidime- and saline-treated controls compared to the moxifloxacin pretreatment that abolished their secretion. In conclusion, moxifloxacin protected cyclophosphamide-injected mice from C. albicans-induced lung infection and significantly reduced pneumonia, weight loss, and mortality despite the lack of direct antifungal activity. This is most likely due to an immunomodulating activity conferred by moxifloxacin, as shown in this model and in our previous studies. Its potential protective role should be studied in patients undergoing chemotherapy and immune suppression.     

Novel Synergistic Treatment of Ethanol Withdrawal Seizures in Rats with Dopamine and Serotonin Agonists

A recent observation in this laboratory of a simultaneous increase in striatal dopamine and a decrease in serotonin in ethanol-dependent rats during ethanol withdrawal prompted studies with combined dopaminergic + serotoninergic agonists to stop withdrawal seizures. Amphetamine (2 mg/kg) + fenfluramine (8 mg/kg) given jointly, but not separately, prevented ethanol withdrawal seizures as effectively as benzodiazepines (chlordiazepoxide), the current drugs of choice. The combination of amphetamine and fenfluramine, unlike chlordiazepoxide, significantly reduced intake of ethanol during and immediately following ethanol withdrawal.     

ISOLATION AND CHARACTERIZATION OF A NEW TRYPSIN-LIKE ENZYME FROM: Tenebrio molitor L. LARVAE

A trypsin-like enzyme (TLE) was separated and purified from Tenebrio molitor larval midgut enzyme solution by ion-exchange chromatography on a DEAE-cellulose column. The purified enzyme was found to be a homogeneous protein by electrophoresis in polyacrylamide gels and on cellulose acetate strips, by electrofocusing in polyacrylamide gels and by SDS-polyacrylamide gel electrophoresis. Its molecular weight was estimated to be 18300 by ultracentrifugal analysis and 24300 on SDS-polyacrylamide gel electrophoresis. It has an isoelectric point 8.0, it contains only four half-cystine residues per molecule and the NH₂-terminal amino acid is isoleucine. TLE possesses a high degree of specificity towards trypsin synthetic substrates such as N-α-benzoyl-DL-arginine p-nitroanilide (BAPNA), p-tosyl-L-arginine methyl ester (TAME) and poly-L-lysine hydrobromide. The optimal pH for TLE activity was found to be 8.0 and the optimal temperature 50° C. Its Km value when assayed on BAPNA was 0.93mM and on TAME 0.08mM. TLE is stable at neutral pHs and its activity is not affected by Ca²⁺ and by 0.01 M 1, 4-dithiothreitol (DTT). It is inactivated by DFP and tosyl-L-lysine chloromethylketone (TLCK) and is fully inhibited by the naturally occurring trypsin inhibitors such as trypsin-and α-chymotrypsin inhibitor (AA) from soybeans, basic pancreatic trypsin inhibitor (BPTI), chick peas trypsin and chymotrypsin inhibitor (CI) and crystalline soybean trypsin inhibitor (CSBTI), forming with them complexes in a molar ratio of 1:1. The Ki value for AA with BAPNA as substrate is 5.87 10^-7 M and for BPTI 7.92 10^-7M. No common antigenic determinants were noted between TLE and bovine trypsin. This finding together with the relatively low number of -S-S- bonds in the TLE molecule indicate that TLE differs in conformation from bovine trypsin.     

The effect of chilling on membrane lipid phase transition in human oocytes and zygotes

BACKGROUND: Chilling injury occurs when the cell membrane undergoes a transition from the liquid state to the gel state. Human oocytes and single-cell zygotes are of similar shape and size but the post-thawing survival rate of oocytes is poorer. We set out to investigate the possible difference in membrane lipid phase transition (LPT) temperature between the two cell types. METHODS: The LPT temperature was measured with a Fourier Transform Infrared analyser, which detects the change in the vibration frequency of the CH2 bond stretches of the membrane lipid molecules during temperature change. The LPT temperatures of unfertilized human oocytes, in vitro-matured oocytes, and immature germinal vesicle (GV) stage oocytes were compared with that of abnormally fertilized human zygotes. RESULTS: The LPT temperatures of zygotes and of mature and immature GV oocytes differ significantly from each other (10.0 +/- 1.2, 16.9 +/- 0.9 and 24.4 +/- 1.6 degrees C respectively; P < 0.05). CONCLUSIONS: Zygotes show a higher resistance to chilling injury compared to oocytes at different developmental stages; this might explain the relatively poor survival rates of cryopreserved human oocytes and indicates the necessity to adjust the cryopreservation protocols in order to minimize cryoinjury.     

Improved immune function with donor B-cell infusion after semi-allogeneic bone marrow transplantation in mice

BACKGROUND: Regeneration of the immune system after bone marrow transplantation (BMT) is a slow process, often prolonged by the development and treatment of graft vs. host disease (GVHD). Donor lymphocyte infusion using allogeneic T-cells is widely applied for the induction of GVHD, which is associated with the desired graft vs. leukemia effect. Due to the slow immune recovery, our objective was to accelerate the immune recovery post-BMT by B-cell injections. METHODS: T-cell-depleted stem cells obtained from female C57BL/6 (B6) mice were transplanted into lethally irradiated (Balb/c x C57BL/6) F-1 female mice. Seven days post-transplantation, murine B-cells of male C57BL/6 origin were infused into the T-cell-depleted chimeras. Thirty and 60 days post-transplantation, PCR analysis of the Y-chromosome was carried out to detect male B-cells in the transplant recipients. In order to evaluate the specific antibody response, the donors were immunized by specific T-cell-dependent and -independent antigens. RESULTS: None of the T-cell-depleted transplanted mice developed GVHD during a follow-up period of 650 days, whereas all non-T-cell-depleted recipients died. At 60 days post-transplantation, significantly higher levels of immunoglobulins (IgA, IgG1, IgG3 isotypes) were seen in chimeras supplemented with male B-cells than in chimeras reconstituted with T-cell-depleted stem cells alone. CONCLUSIONS: Our data document the feasibility of administering B-cell therapy post-allogeneic BMT to improve recovery of the humeral arm of the immune system while avoiding GVHD. Furthermore, post-transplant B-cell administration may have an important impact as an alternative to IV immunoglobulin infusions.