Augmentation of oxidant injury to human pulmonary epithelial cells by the Pseudomonas aeruginosa siderophore pyochelin.

Pseudomonas aeruginosa causes acute and chronic infections of the human lung, with resultant tissue injury. We have previously shown that iron bound to pyochelin, a siderophore secreted by the organism to acquire iron, is an efficient catalyst for hydroxyl radical (HO.) formation and augments injury to pulmonary artery endothelial cells resulting from their exposure to superoxide (O2.) and/or H2O2. Sources for O2-. and H2O2 included phorbol myristate acetate (PMA)-stimulated neutrophils and pyocyanin. Pyocyanin, another P. aeruginosa secretory product, undergoes cell-mediated redox, thereby forming O2-. and H2O2. In P. aeruginosa lung infections, damage to airway epithelial cells is probably more extensive than that to endothelial cells. Therefore, we examined whether ferripyochelin also augments oxidant-mediated damage to airway epithelial cells. A549 cells, a human type II alveolar epithelial cell line, was exposed to H2O2, PMA-stimulated neutrophils, or pyocyanin, and injury was determined by release of 51Cr from prelabeled cells. Ferripyochelin significantly increased (> 10-fold) oxidant-mediated cell injury regardless of whether H2O2, neutrophils, or pyocyanin was employed. Apo-pyochelin was not effective, and ferripyochelin was not toxic by itself at the concentrations employed. Spin trapping with alpha-(4-pyrridyl-1-oxide)-N-t-butyl-nitrone-ethanol confirmed the generation of HO., and injury was decreased by a variety of antioxidants, including superoxide dismutase, catalase, and dimethylthiourea. These data are consistent with the hypothesis that the presence of ferripyochelin at sites of P. aeruginosa lung infection could contribute to tissue injury through its ability to promote HO.-mediated damage to airway epithelial cells.     

Argyrophilic cells in 202 human mucinous breast carcinomas. Relation to histopathologic and clinical factors

Two hundred two human, mucinous breast carcinomas were investigated for the presence of argyrophilic granules, and these granules were found in 25% of the cases. The granules were located in the cytoplasm and were heterogeneously distributed within the tumors. Tumors with granules were otherwise morphologically indistinguishable from those tumors without granules. The recurrence-free survival was independent of the presence of granules, and no relation was found to other clinical or histopathologic factors. Tumors with granules were found to be estrogen-receptor positive, and they appear to have a slightly less aggressive growth pattern than tumors without granules, but the difference is far from being statistically significant. It is concluded that there is no convincing evidence that this group of primary breast carcinomas with argyrophilia originates from APUD cells.     

Neonatal outcome in a Danish national cohort of 3438 IVF/ICSI and 10,362 non-IVF/ICSI twins born between 1995 and 2000

BACKGROUND: In Denmark, one-third of twin pregnancies are the result of IVF/ICSI treatment. Limited data on neonatal outcome in IVF/ICSI twins are available in the literature. METHODS: A register study was conducted on neonatal morbidity and mortality in a complete national twin cohort including all 3438 (3393 live-born) IVF/ICSI and 10,362 (10,239 live-born) non-IVF/ICSI twins born between 1995 and 2000. Twins were identified in the National Medical Birth Registry and dichotomized into IVF/ICSI and non-IVF/ICSI by cross-reference with the Danish IVF Registry. Data on neonatal morbidity and mortality were retrieved from the Danish Patient Registry and the Danish Registry of Causes of Deaths. In order to exclude monozygotic twins, sub-analyses on unlike-sex twins were conducted. RESULTS: A birth weight discordance of >20% was observed in 20.6% of IVF/ICSI versus 15.7% of control twin pairs (P < 0.001). The risk of discordant birth weight >20% was OR 1.29 (95% CI 1.04-1.58) in unlike-sex IVF/ICSI twins versus control twins. The risk of delivery at <37 completed weeks and birth weight <2500 g was similar in the two cohorts; however, in unlike-sex IVF/ICSI versus control twins the risk of delivery at <37 weeks and birth weight <2500 g was OR 1.22 (95% CI 1.09-1.38) and OR 1.25 (1.11-1.40) respectively. After stratification for maternal age and parity, these risks disappeared. IVF/ICSI twins carried a higher risk of admittance to a neonatal intensive care unit (NICU) than control twins (OR 1.18, 95% CI 1.09-1.27), and this was even more pronounced in unlike-sex twins [OR 1.34 (95% CI 1.19-1.51)]. No differences were observed in malformation or mortality rates between the two cohorts. CONCLUSIONS: Despite higher birth weight discordance and more NICU admissions among IVF/ICSI twins, neonatal outcome in IVF/ICSI twins seems to be comparable with that of non-IVF/ICSI twins, when only dizygotic twins were considered in the comparisons.     

Cytomegalovirus infection in heart transplant recipients: Preliminary results of a controlled trial of intravenous gamma globulin

Cytomegalovirus (CMV) infection is a major problem during the first twelve weeks after cardiac transplantation. Reactivation of endogenous virus, blood transfusion, and the transplanted heart are sources for CMV infection. Not only can disseminated CMV infection contribute directly to mortality, but CMV infection predisposes to superinfection with bacterial and fungal pathogens. Studies in mice, the premature neonate, and bone marrow transplant recipients suggest that passive immunization with CMV antibody has a modifying effect on CMV infection. By prophylactic administration of intravenous immune globulin in a controlled randomized fashion to cardiac transplant recipients we will address the question of whether passively acquired antibody prevents or modifies infection with CMV or other viral, bacterial, and fungal infections. Thirteen patients undergoing cardiac transplantation at Stanford University were randomized to receive or not receive intravenous immune globulin (IGIV) at a dose of 20 ml/kg twenty-four hours post transplantation and then weekly thereafter for a period of 10 weeks. Six patients seronegative for CMV antibody were randomized separately from seven who were seropositive for CMV antibody. Seven patients randomly selected from these two groups received IGIV. In patients seronegative for CMV, administration of IGIV resulted in serum titers of 1:10,000–1:30,000 measured by radioimmunoassay. Antibody titers were maintained at levels of 1:10,000 to 1:30,000 throughout the 10 week period post transplantation. Antibody remained detectable up to 8 weeks after the last infusion. No significant increases in CMV antibody levels were detectable after IGIV administration in patients seropositive for CMV antibody prior to transplantation. The administration of IGIV in thirty-two large and repeated doses was safe and well tolerated in cardiac transplant recipients. Serum levels of CMV antibody comparable to those observed in normal CMV seropositive individuals were achieved in CMV seronegative transplant recipients and were maintained throughout the period of greatest risk for CMV infection.     

Constitutional and mosaic large NF1 gene deletions in neurofibromatosis type 1.

A set of neurofibromatosis type 1 (NF1) patients was screened for large NF1 gene deletions by comparing patient and parent genotypes at 10 intragenic polymorphic loci. Of 67 patient/parent sets (47 new mutation patients and 20 familial cases), five (7.5%) showed loss of heterozygosity (LOH), indicative of NF1 gene deletion. These five patients did not have severe NF1 manifestations, mental retardation, or dysmorphic features, in contrast to previous reports of large NF1 deletions. All five deletions were de novo and occurred on the maternal chromosome. However, two patients showed partial LOH, consistent with somatic mosaicism for the deletion, suggesting that mosaicism may be more frequent in NF1 than previously recognised (and may have bearing on clinical severity). We suggest that large NF1 deletions (1) are not always associated with unusual clinical features, (2) tend to occur more frequently on maternal alleles, and (3) are an important mechanism for constitutional and somatic mutations in NF1 patients.     

The sensitivity and specificity of the Major Depression Inventory, using the Present State Examination as the index of diagnostic validity

BACKGROUND: A self-rating inventory has been developed to measure DSM-IV and ICD-10 diagnoses of major (moderate to severe) depression by the patients' self-reported symptoms. This Major Depression Inventory (MDI) can be scored both according to the DSM-IV and the ICD-10 algorithms for depressive symptomatology and according to severity scales by the simple total sum of the items. METHODS: The Schedule for Clinical Assessment in Neuropsychiatry (SCAN) was used as index of validity for the clinician's DSM-IV and ICD-10 diagnosis of major (moderate to severe) depression. The sensitivity and specificity of MDI was assessed in a sample of 43 subjects covering a spectrum of depressive symptoms. RESULTS: The sensitivity of the MDI algorithms for major depression varied between 0.86 and 0.92. The specificity varied between 0.82 and 0.86. When using the total score of MDI the optimal cut-off score was estimated 26 and the total score was shown to be a sufficient statistic. LIMITATIONS: The sample of subjects was limited. Patients with psychotic depression were not included. CONCLUSION: The MDI was found to have a sensitivity and specificity which is acceptable. The questionnaire is brief and can be scored diagnostically by the DSM-IV and ICD-10 algorithms as well as by its simple total score.     

Identification and Characterization of a 29-Kilodalton Protein from Mycobacterium tuberculosis Culture Filtrate Recognized by Mouse Memory Effector Cells

Culture filtrate proteins from Mycobacterium tuberculosis induce protective immunity in various animal models of tuberculosis. Two molecular mass regions (6 to 10 kDa and 24 to 36 kDa) of short-term culture filtrate are preferentially recognized by Th1 cells in animal models as well as by patients with minimal disease. In the present study, the 24- to 36-kDa region has been studied, and the T-cell reactivity has been mapped in detail. Monoclonal antibodies were generated, and one monoclonal antibody, HYB 71-2, with reactivity against a 29-kDa antigen located in the highly reactive region below the antigen 85 complex was selected. The 29-kDa antigen (CFP29) was purified from M. tuberculosis short-term culture filtrate by thiophilic adsorption chromatography, anion-exchange chromatography, and gel filtration. In its native form, CFP29 forms a polymer with a high molecular mass. CFP29 was mapped in two-dimensional electrophoresis gels as three distinct spots just below the antigen 85 complex component MPT59. CFP29 is present in both culture filtrate and the membrane fraction from M. tuberculosis, suggesting that this antigen is released from the envelope to culture filtrate during growth. Determination of the N-terminal amino acid sequence allowed cloning and sequencing of the cfp29 gene. The nucleotide sequence showed 62% identity to the bacteriocin Linocin from Brevibacterium linens. Purified recombinant histidine-tagged CFP29 and native CFP29 had similar T-cell stimulatory properties, and they both elicited the release of high levels of gamma interferon from mouse memory effector cells isolated during the recall of protective immunity to tuberculosis. Interspecies analysis by immunoblotting and PCR demonstrated that CFP29 is widely distributed in mycobacterial species.     

Effects of oxytocin in normal man during low and high sodium diets

AIM: We tested the hypothesis that oxytocin in normal man causes natriuresis by means of nitric oxide and/or atrial natriuretic peptide. METHODS: Normal male subjects were investigated after 4 days of sodium controlled diets (30 mmol sodium chloride day(-1), n = 8 or 230 mmol sodium chloride day(-1), n = 6). Oxytocin was infused intravenously (1 pmol kg(-1) min(-1) for 240 min). RESULTS: Mean arterial blood pressure, heart rate and glomerular filtration rate by clearance of chromium-labelled ethylenediaminetetraacetate remained stable. Plasma oxytocin increased from 2 to 3 pg mL(-1) to around 50 pg mL(-1). Oxytocin decreased urine flow (4.2 +/- 0.2--0.75 +/- 0.11 and 4.6 +/- 1.3-1.4 +/- 0.6 mL min(-1), low- and high-salt diet, respectively). During low-salt conditions, oxytocin reduced sodium and potassium excretion (11 +/- 2--4 +/- 2 and 93 +/- 19--42 +/- 3 micromol min(-1), respectively). Plasma renin, angiotensin II, aldosterone and renal excretion of metabolites of nitric oxide (nitrate and nitrite) all decreased. Plasma atrial natriuretic peptide and cyclic guanosine monophosphate were unchanged. A similar pattern was obtained during high-salt conditions but in this case the antinatriuresis was not different from that occurring during the corresponding time control series. CONCLUSIONS: The data reject the hypothesis. In contrast, we found significant antinatriuretic, antikaliuretic and antidiuretic effects, which were not mediated by the renin-angiotensin-aldosterone system, atrial natriuretic peptide, systemic haemodynamics, or processes increasing urinary excretion of metabolites of nitric oxide. The natriuretic effect of oxytocin found in laboratory animals is species-specific.