High susceptibility to bacterial infection, but no liver dysfunction, in mice compromised for hepatocyte NF-kappaB activation.

Based on the essential involvement of NF-kappaB in immune and inflammatory responses and its apoptosis-rescue function in normal and malignant cells, inhibitors of this transcription factor are potential therapeutics for the treatment of a wide range of diseases, from bronchial asthma to cancer. Yet, given the essential function of NF-kappaB in the embryonic liver, it is important to determine its necessity in the liver beyond embryogenesis. NF-kappaB is normally retained in the cytoplasm by its inhibitor IkappaB, which is eliminated upon cell stimulation through phosphorylation-dependent ubiquitin degradation. Here, we directed a degradation-resistant IkappaBalpha transgene to mouse hepatocytes in an inducible manner and showed substantial tissue specificity using various means, including a new method for live-animal imaging. Transgene expression resulted in obstruction of NF-kappaB activation, yet produced no signs of liver dysfunction, even when implemented over 15 months. However, the transgene-expressing mice were very vulnerable both to a severe immune challenge and to a systemic bacterial infection. Despite having intact immunocytes and inflammatory cells, these mice were unable to clear Listeria monocytogenes from the liver and succumbed to sepsis. These findings indicate the essential function of the hepatocyte through NF-kappaB activation in certain systemic infections, possibly by coordinating innate immunity in the liver.

Morphogenesis in Trichoderma: suppression of photoinduction by 5-fluorouracil.

Sporulation in the fungus Trichoderma viride is inducible with a short light pulse. 5-Fluorouracil applied prior to photoinduction and removed thereafter suppressed sporulation without greatly aflecting growth. This compound also halved the rate of incorporation of uracil-C(14) into RNA but did not change the ratio of uridylic to cytidylic acid. The effect of 5-fluorouracil was counteracted by uracil but not by thymidine. This supports the hypothesis that 5-fluorouracil affects RNA rather than DNA.

Removal of Uranium(VI) from Solution by Fungal Biomass and Fungal Wall-Related Biopolymers.

Penicillium digitatum mycelium can accumulate uranium from aqueous solutions of uranyl chloride. Azide present during the uptake tests does not inhibit the process. Killing the fungal biomass in boiling water or by treatment with alcohols, dimethyl sulfoxide, or potassium hydroxide increases the uptake capability to about 10,000 parts per million (dry weight). Formaldehyde killing does not enhance the uranium uptake. The inference that wall-binding sites were involved led to the testing of uranium uptake by chitin, cellulose, and cellulose derivatives in microcolumns. All were active, especially chitin.

Brain neurotransmitters in an animal model with postpartum depressive-like behavior.

Post-Partum Depression (PPD) occurs in 15% of pregnancies and its patho-physiology is not known. We studied female BALB/c ("depressive") and C57BL/6 (control) mice as a model for PPD and assessed their behavior and correlates with brain neurotransmitters (NTs) - norepinephrine, dopamine, serotonin and intermediates, during the pre-pregnancy (PREP), pregnancy (PREG) and post-partum (PP) periods. Depressive-like behavior was evaluated by the Open Field (OFT), Tail Suspension (TST) and Forced Swim (FST) tests. Neurotransmitters (NTs) were determined in the striatum (care-giving), hippocampus (cognitive function) and hypothalamus (maternal care & eating behavior). In the BALB/c mice, while their performance in all behavioral tests was significantly reduced during pregnancy and P-P indicative of the development of depressive-like responses, no changes were observed in the C57BL/6 mice. Changes in NTs in BALB/C were as follows: PREP, all NTs in the three brain areas were decreased, although an increase in dopamine release was observed in the hippocampus. PREG: No changes were observed in the NTs except for a decrease in 5-HT in the striatum. P-P: striatum, low 5-HT, NE and dopamine; Hippocampus: low 5-HT, NE and high Dopamine; hypothalamus: all NTs increased, especially NE. Following pregnancy and delivery, the BALB/c mice developed depressive-like behavior associated with a significant decrease in 5-HT, dopamine and NE in the striatum and 5-HT and NE in the hippocampus. Dopamine increased in the latter together with a significant increase in all NTs in the hypothalamus. These findings suggest that the development of PPD may be associated with NT changes. Normalization of these alterations may have a role in the treatment of PPD.

The CXCR4 inhibitor BL-8040 induces the apoptosis of AML blasts by downregulating ERK, BCL-2, MCL-1 and cyclin-D1 via altered miR-15a/16-1 expression.

CXCR4 is a key player in the retention and survival of human acute myeloid leukemia (AML) blasts in the bone marrow (BM) microenvironment. We studied the effects of the CXCR4 antagonist BL-8040 on the survival of AML blasts, and investigated the molecular mechanisms by which CXCR4 signaling inhibition leads to leukemic cell death. Treatment with BL-8040 induced the robust mobilization of AML blasts from the BM. In addition, AML cells exposed to BL-8040 underwent differentiation. Furthermore, BL-8040 induced the apoptosis of AML cells in vitro and in vivo. This apoptosis was mediated by the upregulation of miR-15a/miR-16-1, resulting in downregulation of the target genes BCL-2, MCL-1 and cyclin-D1. Overexpression of miR-15a/miR-16-1 directly induced leukemic cell death. BL-8040-induced apoptosis was also mediated by the inhibition of survival signals via the AKT/ERK pathways. Importantly, treatment with a BCL-2 inhibitor induced apoptosis and act together with BL-8040 to enhance cell death. BL-8040 also synergized with FLT3 inhibitors to induce AML cell death. Importantly, this combined treatment prolonged the survival of tumor-bearing mice and reduced minimal residual disease in vivo. Our results provide a rationale to test combination therapies employing BL-8040 and BCL-2 or FLT3 inhibitors to achieve increased efficacy of these agents.

Air-stable PbSe/PbS and PbSe/PbSexS1-x core-shell nanocrystal quantum dots and their applications.

The optical properties and functionality of air-stable PbSe/PbS core-shell and PbSe/PbSexS1-x core-alloyed shell nanocrystal quantum dots (NQDs) are presented. These NQDs showed chemical robustness over months and years and band-gap tunability in the near infrared spectral regime, with a reliance on the NQD size and composition. Furthermore, these NQDs exhibit high emission quantum efficiencies of up to 65% and an exciton emission band that is narrower than that of the corresponding PbSe NQDs. In addition, the emission bands showed a peculiar energy shift with respect to the relevant absorption band, changing from a Stokes shift to an anti-Stokes shift, with an increase of the NQD diameter. The described core-shell structures and the corresponding PbSe core NQDs were used as passive Q-switches in eye-safe lasers of Er:glass, where they act as saturable absorbers. The absorber saturation investigations revealed a relatively large ground-state cross-section of absorption (sigma gs = 10(-16) - 10(-15) cm2) and a behavior of a "fast" absorber with an effective lifetime of tau eff approximately 4.0 ps is proposed. This lifetime is associated with the formation of multiple excitons at the measured pumping power. The product of sigma gs and tau eff enables sufficient Q-switching performance and tunability in the near infrared spectral regime. The amplified spontaneous emission properties of PbSe NQDs were examined under continuous illumination by a diode laser at room temperature, suitable for standard device conditions. The results revealed a relatively large gain parameter (g = 2.63 - 6.67 cm-1). The conductivity properties of PbSe NQD self-assembled solids, annealed at 200 degrees C, showed an Ohmic behavior at the measured voltages (up to 30 V), which is governed by a variable-range-hopping charge transport mechanism.

Erythropoietin-induced polycythemia in athymic mice following transplantation of a human renal carcinoma cell line.

An established cloned human renal carcinoma line RC-1, which has been continuously maintained in culture for several years and which produces erythropoietin, was injected s.c. into BALB/c athymic mice and produced tumors. Tumorigenicity was directly correlated with the number of RC-1 cells inoculated. Tumor cell histology resembled the original patient-derived tumor. Tumor-bearing mice developed hepatosplenomegaly and significant reticulocytosis with elevated hemoglobin and hematocrit values that were proportional to tumor mass. In addition, red cell mass and blood volume of nude mice increased over 100% as compared to control mice or to animals bearing nonrelevant neoplasms. Large amounts of immunoreactive erythropoietin could be extracted from the nude mouse RC-1 tumors. These results indicate that the RC-1 cell line is tumorigenic and produces biologically active erythropoietin in vivo in athymic mouse hosts, thus providing a reproducible model to study ectopic erythropoietin production and its regulation in vivo.

Purification and Characterization of the Voltage-Dependent Anion-Selective Channel Protein from Wheat Mitochondrial Membranes.

An approximately 29-kD protein was purified from the membrane fraction of wheat (Triticum aestivum cv Dganit) mitochondria by the utilization of standard liquid chromatography techniques. The protein, designated MmP29 for mitochondrial membrane protein having a molecular mass of approximately 29 kD, exhibited cationic properties in a buffering solution, adjusted to pH 7.5. This positive charge enabled its passage through a diethylaminoethyl column, without interaction with the positively charged matrix. Subsequently, this protein was separated from the remaining polypeptides by a preferential elution from a hydroxylapatite/celite mixed column. Reconstituted liposomes containing this protein were characterized as being permeable to 8-amino-naphthalene 1,3,6-trisulfonic acid disodium salt (Mr 445) but non-permeable to dextran fluorescein (Mr 40,000). Additionally, MmP29 was inserted into planar phospholipid membranes, and anion-selective, voltage-dependent channels were demonstrated. All of the MmP29 properties mentioned highly resemble voltagedependent, anion-selective channel (VDAC) proteins, suggesting that MmP29 is the mitochondrial outer membrane VDAC protein of wheat.

Tissue-Specific Expression of the Tobacco Mosaic Virus Movement Protein in Transgenic Potato Plants Alters Plasmodesmal Function and Carbohydrate Partitioning.

Transgenic potato (Solanum tuberosum) plants expressing the movement protein (MP) of tobacco mosaic virus (TMV) under the control of the promoters from the class I patatin gene (B33) or the nuclear photosynthesis gene (ST-LS1) were employed to further explore the mode by which this viral protein interacts with cellular metabolism to change carbohydrate allocation. Dye-coupling experiments established that expression of the TMV-MP alters plasmodesmal function in both potato leaves and tubers when expressed in the respective tissues. However, whereas the size-exclusion limit of mesophyll plasmodesmata was increased to a value greater than 9.4 kD, this size limit was smaller for plasmodesmata interconnecting tuber parenchyma cells. Starch and sugars accumulated in potato leaves to significantly lower levels in plants expressing the TMV-MP under the ST-LS1 promoter, and rate of sucrose efflux from petioles of the latter was higher compared to controls. It is interesting that this effect was expressed only in mature plants after tuber initiation. No effect on carbohydrate levels was found in plants expressing this protein under the B33 promoter. These results are discussed in terms of the mode by which the TMV-MP exerts its influence over carbon metabolism and photoassimilate translocation, and the possible role of plasmodesmal function in controlling these processes.

Quinidine-induced vasculitis.

Four patients developed nonthrombocytopenic purpura two to three weeks after initiation of quinidine therapy. The skin lesions disappeared and did not recur after cessation of quinidine therapy. Histologic examination revealed leukocytoclastic vasculitis with deposition of C3, IgA, and/or IgM in the small dermal vessels. Since quinidine purpura is usually associated with thrombocytopenia, the possibility of leukocytoclastic vasculitis as an additional cause of purpura is stressed.

Relapsing hepatitis A. Review of 14 cases and literature survey.

We have reviewed our experience with 14 cases of relapsing hepatitis A (RH-A), as well as 68 cases reported in the literature. Relapse occurs in 3 to 20% of patients with acute hepatitis A, and rarely takes the form of a polyphasic disease (multiple relapses). After a stage of typical hepatitis A, remission phase ensues, with partial or complete resolution of clinical and biochemical manifestations. Relapse usually occurs after a short period (usually less than 3 weeks). Relapse is usually clinically milder than the first phase, with variable liver function abnormalities and a tendency toward more marked cholestatic features. Not uncommonly, immune manifestations occur during this phase, including purpura, nephritis, and arthralgia, with common laboratory findings of rheumatoid factor as well as false-positive reaction to HCV-EIA tests. The clinical course in relapsing hepatitis A is almost always benign, and uneventful recovery is the rule with few exceptions. Steroid treatment, first reported in the present series, resulted in marked clinical improvement. Preliminary results suggest that R-HA is associated with a continuing viremia as well as shedding of virus in stools during the relapse phase. The pathogenesis of R-HA probably involves an interaction between persistent viral infection and immune mechanisms responding to the continuing antigenic stimulation.

Failure of long-term digitalization to prevent rapid ventricular response in patients with paroxysmal atrial fibrillation.

Digitalis is frequently prescribed to patients with paroxysmal atrial fibrillation to reduce the ventricular rate during subsequent paroxysms. To verify the validity of this assumption, we determined the ventricular rate during paroxysmal atrial fibrillation in 13 patients receiving long-term digoxin therapy (mean plasma digoxin level + 1.28 +/- 0.4 ng/ml) and compared it with that of a group of 14 patients who had not taken digoxin or beta-adrenergic and calcium-blocking agents before the attack. The treated and the untreated groups were similar statistically. The mean ventricular rate of the digitalized patients was 121 +/- 15 beats per minute, while that of the patients in the control group was 118 +/- 16 beats per minute. It is concluded that long-term digoxin therapy is not effective in reducing the ventricular response in patients with paroxysmal atrial fibrillation despite adequate therapeutic levels.

Nifedipine and prazosin in the management of pulmonary hypertension in CREST syndrome.

A 62-year-old woman with CREST syndrome and isolated pulmonary hypertension (without evidence of interstitial lung disease) underwent right heart catheterization to evaluate the effect of steroid and vasodilator treatment on hemodynamic parameters. During 12 weeks of prednisone treatment in a dosage of 40 mg daily, her condition markedly deteriorated clinically and hemodynamically as manifested by pulmonary artery pressure (PAP), pulmonary vascular resistance (PVR), cardiac output (CO), mixed venous O2 saturation, and systemic vascular resistance (SVR). Successive trials with various vasodilators demonstrated ineffectiveness of isosorbide dinitrate and phenoxybenzamine, whereas nifedipine was effective in a 15-mg single dose, and prazosin 1 mg was partially effective in reducing PVR, SVR, and increasing CO and mixed venous O2 saturation. The combination of nifedipine 10 mg and prazosin 0.5 mg given alternately every four hours for 48 hours was the most effective in reducing PVR and PAP. Clinical response was favorable as well until treatment with medications was discontinued due to gastrointestinal side effects one month later.

Lack of known hepatitis virus in hepatitis-associated aplastic anemia and outcome after bone marrow transplantation.

Viral infection has been shown to induce aplastic anemia, unidentified types of hepatitis being the most common cause for aplastic anemia-associated viral hepatitis. The survival rate for this group of patients after bone marrow transplantation with stem cells from an HLA-matched sibling is not well known. The aim of this study was to determine the prevalence of hepatitis G virus (HGV) and transfusion transmitted virus (TTV) infection in non-A, non-B, non-C hepatitis associated-aplastic anemia (HAAA) patients, and to define the role of bone marrow transplantation (BMT) as a therapeutic modality for this disease. Sixty-eight patients (43 males and 25 females) with aplastic anemia, underwent allogeneic BMT at the Hadassah University Hospital between 1981 and 1997. Onset of hepatitis was defined as jaundice and elevated alanine aminotransaminase (ALT) levels. Onset of aplastic anemia was defined as the first date on which varying degrees of pancytopenia occurred: hemoglobin level below 10 g/dl, WBC below 2 x 10(9)/l and low platelet count 10 x 10(10)/l. Serial serum samples from HAAA patients were assayed for virological and/or serological markers of hepatitis A, B, C, D, E, G viruses, TTV and parvovirus B19. Seventeen of the 68 patients with aplastic anemia (25%) suffered from hepatitis, 12 males and five females, ages 5 to 36 years. The mean interval between onset of hepatitis and first indication of aplastic anemia was 62 days (range 14-225 days). The development of aplastic anemia was unrelated to age, sex or severity of hepatitis. Ten of the 17 patients (59%) achieved complete ALT recovery prior to the diagnosis of aplastic anemia. Serum samples were available for 15 patients; none had evidence of acute or active hepatitis A, B, C, D, E, G and TTV virus infection at the time of diagnosis. Parvovirus B19 DNA sequences were not detectable in 10 of 12 tested cases; two positive results were detected in serum samples obtained after blood transfusion, making the analysis of these positive results difficult. All 17 patients underwent BMT. The mean post-BMT follow-up period was 38 months (range 1 day-123 months), five patients (30%) died 1 to 160 days post BMT, and 12 (70%) are alive 31 to 123 months after BMT. Relapsing hepatitis was not observed in any of the patients. In conclusion, HAAA is a disease of the young and the etiologic agent associated with HAAA remains unknown. HGV, TTV and parvovirus B19 sequences were not detected in any of the HAAA cases. The survival rate after BMT with stem cells from an HLA-matched sibling is similar to that for patients with non-hepatitis-associated aplastic anemia.

Hepatitis c virus infection in employees of a large university hospital in Israel.

OBJECTIVE: To assess whether hospital work constitutes a risk factor for hepatitis C virus (HCV) infection among employees of a large hospital in Israel. DESIGN: Seroprevalence survey. SETTING: A 1,006-bed, tertiary-care university hospital in Jerusalem. PARTICIPANTS: All 5,444 employees (18-65 years old) were eligible; 4,287 (79%) participated in the survey. METHODS: Sera were tested for antibodies to HCV (anti-HCV) using a third-generation enzyme immunoassay. A third-generation strip immunoblot assay was used for confirmation. Participants were interviewed regarding their occupational history, and they completed a self-administered questionnaire covering history of non-occupational exposure to blood and country of birth. Other demographic information was obtained from the personnel department. Rates and odds ratios (ORs) were calculated, and multivariate logistic-regression analyses were performed to adjust for potential confounding variables. RESULTS: Anti-HCV was found in 0.9% of employees (37/4,287; 95% confidence interval, 0.6-1.1), ranging from 0.1% among those born in Israel to 5.7% among those born in Central Asia. After age, gender, social status, country of birth, and history of blood transfusion were controlled for in a logistic regression, occupational exposure to blood > or = 10 years was significantly associated with the presence of antibodies (OR, 2.6; P=.01). Presence of anti-HCV also was associated with country of birth (range: Israel OR, 1; West OR, 3.8 [P=.1]; Central Asia OR, 48.6 [P<.0001]) and history of blood transfusion (OR, 2.7; P=.01). No significant associations were found between anti-HCV and age, gender, social status, history of tattoo, acupuncture, current occupation, department, exposure to blood in current occupation, adherence to safety precautions, or history of percutaneous injury. The association with length of exposure was stronger (OR, 3.6; P=.01) when the same logistic regression was run excluding the outlier ethnic group of Central Asia. CONCLUSIONS: Hospital work does not seem to constitute a major risk factor for HCV infection in Israel today. A higher prevalence of anti-HCV among employees with longer versus shorter lengths of occupational exposure may be due to a cumulative effect of exposure over the years. Infection control efforts in recent years may have contributed to this association.

Serum creatine kinase activity following a 120-km march.

Serum creatine kinase (SCK) was measured in 19 well-trained athletes before, immediately after and 24 and 72 h after a 120-km, non-stop march. The mean level before the march was 97.6 +/- 46.6 (SD), immediately after the march 1072.8 +/- 708 microns/l, and 72 h later 185.6 +/- 106.2 microns/l. It is concluded that elevated SCK levels may persist for 72 h after a long march.

Clinical, psychological and thallium stress studies in patients with chest pain and normal coronary arteries.

The clinical and psychological profiles of 36 consecutive patients with chest pain and normal coronary arteries (study group) were compared to those of 34 patients with chest pain and significant coronary arterial disease (control group). All 70 patients were hospitalized for chest pain at least once prior to coronary angiography. The features of a typical episode of chest pain were similar in the normal coronary arteries and coronary arterial disease groups, but the female patients with normal coronary arteries had a shorter duration of a typical episode of chest pain, and the male patients with normal coronary arteries had a lower frequency of positive effort tests. Psychological testing showed the women with normal coronary arteries to have a tendency to increased somatization, anxiety, and a lower ability to identify origin of difficulties. The patients in the normal coronary and coronary arterial disease groups had psychological profiles typical of patients with chronic somatic disease. A psychiatric interview demonstrated an increased frequency of depressive trait (score 0-2) in the normal women (0.6 +/- 0.8 vs 0, P less than 0.05), and a tendency to increased somatization, anxiety, and sleeping disorders. Increased somatization was found in the normal coronary men (1.1 +/- 0.7 vs 0.5 +/- 0.7, P less than 0.05). Twenty-five patients of the normal coronary group underwent quantitative thallium stress studies, and 13 patients (52%) had evidence of stress-induced myocardial perfusion defect. There were no differences in the clinical and psychological profiles of the patients with normal and those with pathological thallium stress tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Case series: hyponatremia associated with moderate exercise.

Exercise-induced hyponatremia is commonly believed to be associated only with extraordinary physical efforts, or particularly strenuous exercise. Hyponatremia complicating moderate exercise has not been described previously. The authors describe the characteristics of seven patients with life-threatening hyponatremia associated with mild to moderate exercise. All patients suffered from nausea, vomiting, agitation, and confusion, appearing during or after moderate physical activity. Grand mal convulsions occurred in five of the patients. In laboratory results, hyponatremia was as low as 115 mEq/L, with a relatively high sodium concentration in the urine. High serum creatine kinase activity levels were found in most of the patients. All patients were discharged in good condition, without neurologic sequela. The authors conclude that hyponatremia is a possible complication of moderate exercise, and not only of endurance sports, and that exercise-induced hyponatremia can produce severe neurologic manifestations. The mechanism of the hyponatremia is unclear, but may be due to a hemodynamically inappropriate stimulus for antidiuretic hormone secretion.

Pancreatitis following hepatitis A vaccination.

We describe a 23-year-old male patient who presented with epigastric abdominal pain, 8 days following vaccination with inactivated hepatitis A virus (Haverix(R)). Clinical and laboratory data confirmed the diagnosis of pancreatitis. Repeat polymerase chain reaction (PCR) for hepatitis A replication was negative. A comprehensive evaluation ruled out other etiologies for pancreatitis. IgM Hepatitis A antibodies did not develop even after 3 months. Pancreatitis following Hepatitis A is a well-known complication of the viremia, but the exact mechanism is controversial. We suggest that the pancreatitis may have been a cellular immunlogical reaction to one of the antigens of hepatitis A virus vaccine, or it might have been caused by the release of mediators of anaphylaxis such as histamine and leucotriens, induced by HAV antigens, resulting in pancreatitis without development of humoral immunization.

Prior hepatitis A virus infection enhances acute hepatitis E virus infection.

The epidemiology and clinical manifestations of hepatitis E virus (HEV) and hepatitis A virus (HAV) are similar. However, two distinct diseases develop after exposure to each one of the viruses, which are apparently unrelated clinically. It is interesting to note that all reported epidemics and single cases of acute HEV infection indicate previous exposure to HAV. This fact leads us to hypothesize that acute HEV infection is dependent on past infection by hepatitis A virus, and that the sequential infections could not solely be explained on independent outbreaks. This hypothesis, where past HAV infection serves to support acute HEV infection, may have current practical implications, and could improve our understanding of the virology and pathophysiology of the disease.