Cytomegalovirus-Associated CD4(+) CD28(null) Cells in NKG2D-Dependent Glomerular Endothelial Injury and Kidney Allograft Dysfunction.

Emerging data suggest that expansion of a circulating population of atypical, cytotoxic CD4(+) T cells lacking costimulatory CD28 (CD4(+) CD28(null) cells) is associated with latent cytomegalovirus (CMV) infection. The purpose of the current study was to increase the understanding of the relevance of these cells in 100 unselected kidney transplant recipients followed prospectively for a median of 54 months. Multicolor flow cytometry of peripheral blood mononuclear cells before transplantation and serially posttransplantation was undertaken. CD4(+) CD28(null) cells were found predominantly in CMV-seropositive patients and expanded in the posttransplantation period. These cells were predominantly effector-memory phenotype and expressed markers of endothelial homing (CX3CR1) and cytotoxicity (NKG2D and perforin). Isolated CD4(+) CD27(-) CD28(null) cells proliferated in response to peripheral blood mononuclear cells previously exposed to CMV-derived (but not HLA-derived) antigens and following such priming incubation with glomerular endothelium resulted in signs of endothelial damage and apoptosis (release of fractalkine and von Willebrand factor; increased caspase 3 expression). This effect was mitigated by NKG2D-blocking antibody. Increased CD4(+) CD28(null) cell frequencies were associated with delayed graft function and lower estimated glomerular filtration rate at end follow-up. This study suggests an important role for this atypical cytotoxic CD4(+) CD28(null) cell subset in kidney transplantation and points to strategies that may minimize the impact on clinical outcomes.

Transitional B lymphocytes are associated with protection from kidney allograft rejection: a prospective study.

Recent cross-sectional studies suggest an important role for transitional B lymphocytes (CD19 + CD24hiCD38hi) in promoting transplant tolerance, and protecting from late antibody-mediated rejection (ABMR). However, prospective studies are lacking. This study enrolled 73 de novo transplant recipients, and collected serial clinical, immunological and biochemical information over 48 ± 6 months. Cell phenotyping was conducted immediately prior to transplantation, and then on five occasions during the first year posttransplantation. When modeled as a time-dependent covariate, transitional B cell frequencies (but not total B cells or "regulatory" T cells) were associated with protection from acute rejection (any Banff grade; HR: 0.60; 95% CI: 0.37-0.95; p = 0.03). No association between transitional B cell proportions and either de novo donor-specific or nondonor-specific antibody (dnDSA; dnNDSA) formation was evident, although preserved transitional B cell proportions were associated with reduced rejection rates in those patients developing dnDSA. Three episodes of ABMR occurred, all in the context of nonadherence, and all associated with in vitro anti-HLA T cell responses in an ELISPOT assay (p = 0.008 versus antibody-positive patients not experiencing ABMR). This prospective study supports the potential relevance of transitional ("regulatory") B cells as a biomarker and therapeutic intervention in transplantation, and highlights relationships between humoral immunity, cellular immunity and nonadherence.

Biomarkers to enhance accuracy and precision of prediction of short-term and long-term outcome after spontaneous intracerebral haemorrhage: a study protocol for a prospective cohort study.

BACKGROUND: Several studies reported prognostic value of biomarker in intracerebral hemorrhagic (ICH) but they are either preliminary observation or inadequately powered to analyse independent contribution of biomarkers over and above clinical and neuroimaging data. OBJECTIVE: To examine whether the biomarker can significantly add to the predictive accuracy of prognosis of ICH. METHOD/DESIGN: In a multi-centric prospective cohort study, 1020 patients with ICH within 72 hours of onset are being recruited. After obtaining written informed consent from patients/proxy, venous blood sample (10 ml) is being collected and analysed for C-reactive protein (CRP) level, S100B, Glial fibrillary acidic protein (GFAP), Troponin, change in leukocyte count and Copeptin levels. The patients are telephonically followed using stroke scales (Barthel Index and modified Rankin Scale) at 3, 6, 12 months and 2 years after the recruitment. DISCUSSION: This protocol will aim at predicting the short term or long term prognosis with the use of clinical, neuroimaging and biomarkers in order to help clinician to stratify patients for early referral or intervention.

Characterizing dilute combustion instabilities in a multi-cylinder spark-ignited engine using symbolic analysis.

Spark-ignited internal combustion engines have evolved considerably in recent years in response to increasingly stringent regulations for emissions and fuel economy. One new advanced engine strategy ustilizes high levels of exhaust gas recirculation (EGR) to reduce combustion temperatures, thereby increasing thermodynamic efficiency and reducing nitrogen oxide emissions. While this strategy can be highly effective, it also poses major control and design challenges due to the large combustion oscillations that develop at sufficiently high EGR levels. Previous research has documented that combustion instabilities can propagate between successive engine cycles in individual cylinders via self-generated feedback of reactive species and thermal energy in the retained residual exhaust gases. In this work, we use symbolic analysis to characterize multi-cylinder combustion oscillations in an experimental engine operating with external EGR. At low levels of EGR, intra-cylinder oscillations are clearly visible and appear to be associated with brief, intermittent coupling among cylinders. As EGR is increased further, a point is reached where all four cylinders lock almost completely in phase and alternate simultaneously between two distinct bi-stable combustion states. From a practical perspective, it is important to understand the causes of this phenomenon and develop diagnostics that might be applied to ameliorate its effects. We demonstrate here that two approaches for symbolizing the engine combustion measurements can provide useful probes for characterizing these instabilities.

Follow-up screening of lead-poisoned children near an auto battery recycling plant, Haina, Dominican Republic.

In August 1997 we performed a follow-up survey of 146 lead-poisoned children from a community near a previously active auto battery recycling smelter in Haina near Santo Domingo, Dominican Republic. Our follow-up survey confirmed a severe incidence of elevated blood lead (BPb) and erythrocyte protoporphyrin/zinc protoporphyrin (EP-ZnPP) levels. The mean BPb level was 32 micrograms/dL and the mean EP-ZnPP level was 128 micrograms/dL. The frequency distribution of BPb showed that only 9% of the children had BPb levels below the currently acceptable 10 micrograms/dL threshold level, 23% had between 10 and 19 micrograms/dL, 40% had between 20 and 39 micrograms/dL, 27% had between 40 and 99 micrograms/dL, and the remainder had > 100 micrograms/dL. These findings are significantly greater than the mean BPb and EP-ZnPP levels of 14 and 35 micrograms/dL, respectively, in a comparison group of 63 children in Barsequillo, 4 miles away. BPb frequency distributions for these groups were < 10 micrograms/dL (42%), 10-19 micrograms/dL (32%), and 20-39 micrograms/dL (16%); in the remaining 10%, BPb levels were between 40 and 99 micrograms/dL. Similarly, the corresponding frequency distribution of EP-ZnPP levels in Haina children were proportional to the severity of lead poisoning and significantly higher than those of the Barsequillo comparison group. This study reveals that at least 28% of Haina children require immediate treatment; of these, 5% with lead levels > 70 micrograms/dL are also at risk for severe neurologic sequelae, and urgent action is imperative.

delta-Aminolevulinic acid dehydratase isozymes and lead toxicity.

ALAD is a zinc metalloenzyme whose inhibition by lead is the first and most sensitive indicator of lead exposure and whose decreased activity has been implicated in the pathogenesis of lead poisoning. This heme biosynthetic enzyme is encoded by a gene located at chromosome 9q34, which has two codominant alleles, ALAD1 and ALAD2. The occurrence of two frequent alleles for ALAD stimulated an investigation into the possible pharmacogenetic role of the enzyme polymorphism in lead poisoning. In a New York City population at high risk for lead exposure, individuals heterozygous or homozygous for the less common allele, ALAD2, had blood lead levels greater than or equal to 30 micrograms/dl more frequently than expected. These findings suggest a potential genetic susceptibility to lead poisoning in individuals with the ALAD 1-2 and 2-2 phenotypes.

Immunosuppression in patients with Barrett's esophagus.

BACKGROUND: Patients with Barrett's esophagus have a higher incidence of esophageal cancer than has the general population. Local tissue injury and exposure to carcinogens presumably play a role in malignant transformation, but the possibility of altered host immune surveillance must also be considered. METHODS: The level of immunoreactivity was investigated in six healthy control subjects; 14 patients with gastroesophageal reflux, seven with and seven without esophagitis; and nine patients with Barrett's esophagus. Parameters studied were (1) T-cell and B-cell function with mitogen-stimulated lymphocyte blastogenesis, (2) immunosuppressive properties of autologous serum, and (3) interleukin-2 production by peripheral blood mononuclear cells. Nutritional status as a possible cause for immunosuppression was assessed by measurement of serum albumin, transferrin, and prealbumin. RESULTS: Patients with Barrett's esophagus had a significant suppression of all T-cell (p less than 0.01) and B-cell function (p less than 0.01) and interleukin-2 production (p less than 0.001) when they were compared to the controls. Interleukin-2 production was also reduced significantly compared to that in patients with gastroesophageal reflux with and without esophagitis (p less than 0.05). No differences were observed in serum immunosuppression or nutritional factors. CONCLUSIONS: Although the immunosuppression observed in the patients with Barrett's esophagus was milder than that found in other immunocompromised states, it may be sufficient to encourage the malignant transformation of Barrett's mucosa.

Manometry of individual segments of the distal esophageal sphincter. Its relation to functional incompetence.

The major components of the lower esophageal sphincter, the pressure it exerts, its total length, and the length of sphincter affected by abdominal pressure are usually expressed as means of several recordings from different radial segments of the sphincter. In segmental manometry, the individual readings for these components in each segment, rather than the mean values, are analyzed. We used segmental manometry to study 50 normal volunteers and 200 patients with symptoms suggestive of gastroesophageal reflux. Of the latter, 100 had increased esophageal acid exposure and 100 did not. An increased number of defective segments was associated with a greater prevalence of increased esophageal acid exposure. Segmental analysis disclosed the same number (52) of defective sphincters (defined as sphincters with two or more defective segments) in the 100 patients with increased acid exposure as did standard analysis. However, the relationship between a defective lower esophageal sphincter and the number of reflux episodes was clearer when a defective sphincter was defined using standard analysis. Segmental analysis of the lower esophageal sphincter has no clear advantage over standard analysis.

Application of a radioimmunoassay screening test for detection and management of phencyclidine intoxication.

A radioimmunoassay procedure has been developed to monitor patients suspected of phencyclidine (PCP) intoxication. Symptoms in 11 patients suspected of phencyclidine intoxication included violent, aggressive behavior with delusions, hallucinations, agitation, and other signs of toxic psychosis. In five subjects serum concentrations of PCP ranged between 0.5 and 40 ng/ml. For laboratory confirmation, ascorbic acid should be administered to the patient after collecting the initial urine specimen. The initial urine and the first and second specimen after acidification should be collected and submitted for analysis. By following this provocative mobilization procedure, phencyclidine has been identified in the first or second postacidification urine when the initial specimen gave either a negative or questionable reaction. Patients reporting to emergency rooms with hallucinations and psychosis and a history of "pot" smoking should be screened for the presence of phencyclidine in their blood and urine. For those cases that turn out to be negative for the phencyclidine group of compounds, other hallucinogenic drugs such as lysergic acid diethylamide, ketamine, mescaline, or psilocybin may be suspect.

Effect of caffeic acid esters on carcinogen-induced mutagenicity and human colon adenocarcinoma cell growth.

Propolis, a honey bee hive product, is thought to exhibit a broad spectrum of activities including antibiotic, antiviral, anti-inflammatory and tumor growth inhibition; some of the observed biological activities may be due to caffeic acid (cinnamic acid) esters that are present in propolis. In the present study we synthesized three caffeic acid esters, namely methyl caffeate (MC), phenylethyl caffeate (PEC) and phenylethyl dimethylcaffeate (PEDMC) and tested them against the 3,2'-dimethyl-4-aminobiphenyl, (DMAB, a colon and mammary carcinogen)-induced mutagenicity in Salmonella typhimurium strains TA 98 and TA 100. Also, the effect of these agents on the growth of human colon adenocarcinoma, HT-29 cells and activities of ornithine decarboxylase (ODC) and protein tyrosine kinase (PTK) was studied. Mutagenicity was induced in Salmonella typhimurium strains TA 98 and TA 100 plus S9 activation using 5 and 10 micrograms DMAB and antimutagenic activities of 0-150 microM MC, 0-60 microM PEC and 0-80 microM PEDMC were determined. The results indicate that MC, PEC and PEDMC were not mutagenic in the Salmonella tester system. DMAB-induced mutagenicity was significantly inhibited with 150 microM MC, 40-60 microM PEC and 40-80 microM PEDMC in both tester systems. Treatment of HT-29 colon adenocarcinoma cells with > 150 microM MC, 30 microM PEC and 20 microM PEDMC significantly inhibited the cell growth and syntheses of RNA, DNA and protein. ODC and PTK activities were also inhibited in HT-29 cells treated with different concentrations of MC, PEC and PEDMC. These results demonstrate that caffeic acid esters which are present in Propolis possess chemopreventive properties when tested in short-term assay systems.

Induction of chromosomal aberrations and sister chromatid exchanges by propane sultone in human lymphocytes in vitro.

Genotoxicological investigation of 1,3-propane sultone was undertaken using human lymphocyte cultures as the test system. Concentrations greater than 1 mM induced appreciable chromosomal aberrations, which increased proportionally to the dose or the duration of treatment. It was also observed that treatment administered at 45 degrees C produced almost 3 times more abnormal cells than at 37 degrees C. The chemical also produced a significantly higher frequency of SCEs.

Cytogenetic activity of some common antioxidants and their interaction with x-rays.

Experiments were designed to investigate the cytogenetic activity of some commonly used phenolic antioxidants, namely BHA, BHT, BMP and PG, all used widely to preserve and stablize food products rich in fats and oils. Barley and onion were used as test systems. The treatments reduced seed germination and induced a significant amount of seedling injury. Only PMP treatments produced a moderate amount of chromosomal aberrations while others failed to do so. Being strong antioxidants it was expected that these compounds would reduce the cytogenetic damage caused by the radiations. Contrary to expectations, however, a significant increase was observed in the radiation damage measured as seed and seedling lethality and chromosomal aberrations. Chemical post-treatments also increased the radiation damage. The damage was, however, reduced with ATP post-irradiation treatment.

Modification of the mutagenic activity of propane sultone by some phenolic antioxidants.

The effects of three phenolic antioxidants, butylated hydroxyanisole, butylated hydroxytoluene and propyl gallate on the mutagenic activity of propane sultone were studied using barley as the test system. The antioxidants produced seedling injury marginally but did not produce any chromosomal aberrations. When administered either prior to propane sultone treatment or in a mixture with it, the seedling injury, chromosomal aberrations, mutations per 100 M1 spikes as well as M2 chlorophyll mutation frequency, were enhanced. On the other hand, however, posttreatments reduced M1 spike sterility, mutations per 100 M1 spikes and M2 chlorophyll mutation frequency. The spectrum of chlorophyll mutations was also broadened in the presence of these antioxidants.

Caffeine potentiation of propane sultone mutagenesis in barley.

Pre- and post-treatments with caffeine enhanced propane sultone (PS)-induced growth damage in barley. The caffeine post-treatments were, however, more effective in potentiating PS-induced growth damage and caused an additive effect on the frequency of chlorophyll mutations.

Lead poisoning from art restoration and pottery work: unusual exposure source and household risk.

Two cases of lead poisoning following exposures in the arts and crafts environment are presented. The first illustrates the impact of an unusual exposure source experienced by a female art conservator while restoring an antique Peruvian tapestry from the Chancay Period (A.D. 1000-1500). The second demonstrates the extension to the artist's family members of a lead hazard associated with pottery work. Noted were a wide spectrum of clinical and biochemical abnormalities, ranging from severe neurological and gastrointestinal symptoms to subtle alterations in the biosynthetic pathway of heme. Marked elevation of the blood lead level (up to 130 mcg/100 mL) was found in the most severe case of lead poisoning. The cases illustrate the need for industrial hygiene measures in this type of work in order to prevent lead intoxication, both in the adult artist and children in the household. However, in some instances of increased lead absorption in persons with lead-related hobbies, sources other than those associated with arts and crafts should be investigated. This alternative is illustrated by a third case, in which firearms training was the more likely source of excessive exposure. Multiple occupational factors must occasionally be considered in evaluating increased lead absorption.

Elevated blood lead and erythrocyte protoporphyrin levels of children near a battery-recycling plant in Haina, Dominican Republic.

A survey of children from a community adjacent to an auto-battery-recycling smelter in Haina, the Dominican Republic, revealed alarming elevations of blood lead (B-Pb) and erythrocyte protoporphyrin (EP-ZnPP) compared with controls. The authors recommend follow-up confirmation and treatment of severely lead-poisoned children, shutdown of the plant, controlled disposal of the hazardous waste from the site, and relocation of the community.

Re-emergence of lead poisoning from contaminated flour in a West Bank Palestinian village.

Although contaminated flour was first described as an important source of endemic lead poisoning in the Middle East almost 20 years ago, the use of lead in community flour mills has not been eliminated and continues to represent a significant environmental risk. The authors describe an outbreak of lead poisoning in a West Bank Palestinian family and draw attention to this unusual but important source of lead exposure. All 13 members of the family (two children and 11 adults), were found to have lead poisoning following hospitalization for "gastroenteritis," headache, joint pain, weight loss, and vision difficulties. Seven females had low hemoglobin levels. Blood lead concentrations ranged from 42 to 84 microg/dL. Household flour samples obtained from a stone mill, previously closed because of lead contamination, contained 2,000 ppm lead. Flour from traditional stone mills reinforced with lead joints remains a potential source for lead poisoning.

Operative management of typhoid perforation in children.

Nine children admitted with typhoid perforation of the ileum underwent a modified ileostomy procedure. The following conclusions were drawn: 1. X-rays do not help in diagnosis in the majority of cases. 2. Blood urea is raised in almost all cases and vigorous attempts should be made to bring its level to normal before operation. 3. Leukopenia does not exist in patients with typhoid perforation; leukocytosis is the usual finding. A positive Widal test is not generally found in these cases and positive blood cultures should not be expected. 4. Ileostomy through the site of perforation, as described, is a simple, safe and short operation in a critically ill patient with a necrotic bowel. Also, resuscitative drugs are not needed.

Lead, erythrocyte protoporphyrin, and ferritin levels in cord blood.

A pilot study was initiated to examine cord blood from approximately 300 newborns of various ethnic groups from two New York City hospitals for lead (Pb), erythrocyte protoporphyrin (EP), ferritin (FRT), and hemoglobin (Hb) levels during 1979 and 1980. Results showed an overall mean Pb level of 8 +/- 4 micrograms/dl, EP level of 61 +/- 26 micrograms/dl [geometric mean (GM) = 66.36], FRT level of 165 +/- 107 ng/ml (GM = 135.99), and a distribution frequency of Hb with nearly 69% between 13.5 and 16.9 g % (mean +/- standard deviation = 15 +/- 1), 20% below 13.4 g % (12 +/- 2 g %), and 11% at or above 17.0 g % (18 +/- 1 g %). Both EP and FRT showed a bimodal distribution. There was a negative correlation between blood EP and plasma FRT levels that was significant at the .03% level. The study also showed that a significant drop in mean cord blood Pb levels occurred compared with earlier studies. Follow up of newborns with mildly elevated Pb and EP levels should be made and screening of mothers for Pb levels during early pregnancy should constitute a part of prenatal care, particularly for those from urban areas with previously demonstrated environmental Pb hazard.

Elevated blood lead in a population near a lead smelter in Kosovo, Yugoslavia.

A survey of residents of a community surrounding a lead smelter has revealed an alarming incidence of elevated blood lead and erythrocyte protoporphyrin concentrations. In particular, children who were less than 3 yr of age were severely affected. Of those children tested in December, 1980, 35% had blood lead concentrations between 50-69 microgram/dl, while an additional 12% had concentrations greater than or equal to 70 microgram/dl, and are, therefore, at risk for severe neurological sequelae.