In vitro displacement of bilirubin by antibiotics and 2-hydroxybenzoylglycine in newborns

Hyperbilirubinemia is frequently observed in neonates, and serious neurological complications such as kernicterus can be precipitated when the concentration of unconjugated bilirubin is abnormally increased. The administration of drugs which bind to albumin and compete with bilirubin can increase the possibility of such a complication. To test the bilirubin-displacing activity of pharmacological agents that are used with newborns, 52 antimicrobial agents were investigated in vitro. A glycine conjugate of salicylate, 2-hydroxybenzoylglycine, which is known to be present at elevated levels in newborns and has a potent bilirubin-displacing property, was used as a positive control agent. Pooled cord serum was used as a source of hyperbilirubinemic serum. A centrifugal ultrafiltration method with semipermeable cones was employed to determine the effects of potential bilirubin-displacing agents on the levels of total bilirubin. 2-Hydroxybenzoylglycine was demonstrated to be the most potent bilirubin-displacing agent. Antibiotics could be classified into four groups: high-level displacers (sulfisoxazole, sulfamethoxazole, dicloxacillin, cefoperazone, and ceftriaxone), intermediate-level displacers (moxalactam, nafcillin, and 14 others), low-level displacers (aztreonam, carbenicillin, and 11 others), and nondisplacers (mezlocillin, cefuroxime, kanamycin, and 15 others). It is concluded that the ultrafiltration method is a rapid and readily reproducible for the determination of bilirubin displacement and that antibiotics with a tendency to displace bilirubin should be avoided in jaundiced newborns whenever appropriate alternatives are available.     

Unilateral pulmonary hemorrhage caused by negative pressure pulmonary edema: A case report

BACKGROUNDUnilateral pulmonary hemorrhage is typically reported in young and healthy men with upper respiratory tract obstruction during anesthesia in special situations. Negative pressure in the lungs is created, resulting in negative pressure pulmonary edema (NPPE). CASE SUMMARYA 78-year-old male patient diagnosed with spinal stenosis was admitted to receive a unilateral laminectomy with bilateral decompression. The patient had been diagnosed with hypertension four years earlier and asthma more than 70 years earlier. We experienced a unilateral alveolar hemorrhage associated with NPPE that occurred in a longstanding asthma patient who bit the intubated endotracheal tube for a short period during posture change at the end of surgery. Because diffuse alveolar hemorrhage accompanied by NPPE was caused in this case by airway obstruction in an older patient with asthma without known risk factors, anesthesiologists should be careful not to induce airway irritation during anesthesia awakening in asthma patients.CONCLUSIONBecause diffuse alveolar hemorrhage accompanied by NPPE can occur, anesthesiologists should take care not to induce airway irritation.     

Comparing the outcomes of radiofrequency ablation and surgery in patients with a single small hepatocellular carcinoma and well-preserved hepatic function

GOALS: To compare the efficacy of radiofrequency ablation (RFA) and surgical resection in a group of patients with a Child-Pugh score of 5 and a single HCC less than 4 cm in diameter. BACKGROUND: Radiofrequency ablation (RFA) has become a popular method for treatment of hepatocellular carcinoma (HCC) and has been applied as an alternative primary therapy to surgical resection. STUDY: We compared outcomes for 148 patients treated with RFA (n = 55) and those treated surgically (n = 93). RESULTS: The rate of local recurrence among patients in the RFA group was significantly higher than in the surgery group (P = 0.005), while the incidence of remote recurrence was similar between the two groups (P = 0.30). The cumulative 1- and 3-year overall survival rates (P = 0.24) and the cumulative 1- and 3-year recurrence-free survival rates (P = 0.54) were not significantly different between the two groups. CONCLUSIONS: Despite a higher rate of local recurrence, RFA was found to be as effective as surgical resection for the treatment of single small HCC in patients with well-preserved liver function, in terms of the incidence of remote recurrence and the patients' likelihood of achieving overall and/or recurrence-free survival.     

Change of platelet activation markers using flow cytometry in patients with hematology/oncology disorders after transfusion

In spite of the frequent need of platelet transfusions, there is limited information on the association of platelet activation markers, in transfused patients with hematology/oncology disorders, with platelet function using flow cytometry. The goal of this study was to evaluate the changes of PAC-1 binding and CD62P expression, with or without agonists in patients after transfusions. Twenty-eight whole blood samples were obtained from 24 patients admitted to the department of Hematology & Oncology and transfused with platelets; these samples were compared to 30 healthy controls. Whole blood samples, either with or without agonists, such as 20 microM adenosine diphosphate (ADP) or 100 microM thrombin receptor activating peptide (TRAP), were stained with the fluorescein conjugated monoclonal antibodies PAC-1 or CD62P. Then, the percent expression for each marker was analysed using flow cytometry. ADP and TRAP induced an increased percentage of CD62P expression and PAC-1 binding after platelet transfusions compared to the samples studied before transfusion, and these findings were lower than those of the healthy controls. However, the expression of platelets without the agonists was not significantly changed, despite the transfusions. Therefore, agonist-induced platelet activation markers, studied by flow cytometry, appear to be more useful for the evaluation of platelet function after transfusions than platelet activation markers without agonists.     

Identification of novel chemoattractant peptides for human leukocytes

Superoxide is the most important armory on the primary defense line of monocytes against invading pathogens, and the identification of new stimuli and the characterization of the regulatory mechanism of superoxide generation are of paramount importance. In this study, we identified 3 novel peptides by screening a synthetic hexapeptide combinatorial library and modification of 1 of the peptides. The isolated peptides that can induce superoxide generation in human monocytes are His-Phe-Tyr-Leu-Pro-Met-CONH(2) (HFYLPM), Met-Phe-Tyr-Leu-Pro-Met-CONH(2) (MFYLPM), and His-Phe-Tyr-Leu-Pro-D-Met-CONH(2) (HFYLPm). All 3 peptides also caused intracellular calcium ([Ca(++)](i)) rise. We tested the specificities of the peptides on cells of different origin by looking at [Ca(++)](i) rise. All 3 peptides acted specifically on leukocytes and not on nonimmune cells. Among leukocytes, HL60 and Jurkat T cells were stimulated specifically by MFYLPM or HFYLPM, respectively. As a physiologic characteristic of the peptides, we observed that all 3 peptides induced chemotactic migration of monocytes. Studying receptor specificity, we concluded that the 3 peptides might act on some shared and some distinct receptor(s) on leukocytes. Studying intracellular signaling set in motion by the peptides revealed that HFYLPM, but not MFYLPM or HFYLPm, induced chemotaxis via phosphatidylinositol-3 kinase and protein kinase C. Because HFYLPM, MFYLPM, and HFYLPm not only exhibit different specificities depending on cell type and status of differentiation but also stimulate cells via distinct receptors and signaling, the 3 novel peptides might be useful tools to study leukocyte activation.     

Functionally significant insulin-like growth factor I receptor mutations in centenarians

Rather than being a passive, haphazard process of wear and tear, lifespan can be modulated actively by components of the insulin/insulin-like growth factor I (IGFI) pathway in laboratory animals. Complete or partial loss-of-function mutations in genes encoding components of the insulin/IGFI pathway result in extension of life span in yeasts, worms, flies, and mice. This remarkable conservation throughout evolution suggests that altered signaling in this pathway may also influence human lifespan. On the other hand, evolutionary tradeoffs predict that the laboratory findings may not be relevant to human populations, because of the high fitness cost during early life. Here, we studied the biochemical, phenotypic, and genetic variations in a cohort of Ashkenazi Jewish centenarians, their offspring, and offspring-matched controls and demonstrated a gender-specific increase in serum IGFI associated with a smaller stature in female offspring of centenarians. Sequence analysis of the IGF1 and IGF1 receptor (IGF1R) genes of female centenarians showed overrepresentation of heterozygous mutations in the IGF1R gene among centenarians relative to controls that are associated with high serum IGFI levels and reduced activity of the IGFIR as measured in transformed lymphocytes. Thus, genetic alterations in the human IGF1R that result in altered IGF signaling pathway confer an increase in susceptibility to human longevity, suggesting a role of this pathway in modulation of human lifespan.     

Is postoperative radiotherapy useful for the rectal carcinoma in the era of total mesorectal excision?

BACKGROUND/AIMS: The exact role of postoperative radiotherapy following curative surgery of rectal carcinoma has been debated. In this retrospective study, we examined the effect of radiotherapy on the survival and recurrence rate of rectal cancer patients who underwent total mesorectal excision. METHODOLOGY: Since June 1994, stage II and III rectal cancer patients have been recommended to receive postoperative chemoradiation. Among 175 consecutive patients who had undergone total mesorectal excision, 120 completed postoperative chemoradiation (group A) and 55 patients declined to receive radiation therapy (group B). For the two groups, survival and recurrence rates were compared. Mean follow-up time was 24.7 months. There was no difference between two groups with regard to sex, mean age, stage of the disease, mean tumor height, type of operation and mean follow-up duration. RESULTS: Overall recurrence rate showed no difference between the two groups (24.0% vs. 25.0%, P = 0.28). Local recurrence rate was also similar (10.0% vs. 6.0%, P = 0.11). There was no significant difference in duration to initial recurrence (14.0 months vs. 11.0 months, P = 0.18). The 5-year disease-free survival was 57% in group A and 63% in group B (P = 0.33). Disease-free survival in stage II was significantly better than in stage III. (78% vs. 42% overall, 70% vs. 37% in group A, 92% vs. 44% for group B, P < 0.01). CONCLUSIONS: In this study, we found no beneficial effect of postoperative radiation therapy following total mesorectal excision for the rectal cancer. So far, the prognosis was critically dependent on the stage rather than presence or absence of radiotherapy after total mesorectal excision.     

Antigen-specific immunotherapy for human papillomavirus 16 E7-expressing tumors grown in the liver

BACKGROUND/AIMS: We have previously reported a recombinant vaccinia-based vaccine (vac-Sig/E7/LAMP-1) that demonstrated a significant anti-tumor effect in a subcutaneous tumor challenge model. Since the liver is one of the most common sites for tumor metastasis and organ microenvironments may modulate tumor cell responses to therapies, the aim of the present study was to evaluate the potency of vac-Sig/E7/LAMP-1 in treating E7-expressing tumors grown in the liver. METHODS: For in vivo tumor prevention experiments, mice were vaccinated intraperitoneally with vac-Sig/E7/LAMP-1 followed by intrahepatic tumor challenge. For in vivo tumor regression experiments, mice were first challenged with tumor cells and then vaccinated with vac-Sig/E7/LAMP-1 intraperitoneally. In addition, enzyme-linked immunospot assays were used to determine the frequency of E7-specific T cell precursors. RESULTS: For in vivo tumor protection experiments, tumor growth was observed in all of the mice vaccinated with wild-type vaccinia and 60% of the mice vaccinated with wild-type E7 vaccinia. All of the mice vaccinated with vac-Sig/E7/LAMP-1 remained tumor-free 30 days after tumor challenge. For the tumor regression assays, all of the mice vaccinated with vac-Sig/E7/LAMP-1 remained tumor-free 30 days after vaccination. In contrast, all of those mice receiving culture medium, wild-type vaccinia, or wild-type E7 vaccinia developed tumors in the liver. In addition, mice vaccinated with vac-Sig/E7/LAMP-1 had the highest E7-specific CD8+ T cell precursors. CONCLUSIONS: Our data suggest that vac-Sig/E7/LAMP-1 is an effective vaccine for controlling E7-expressing tumors grown in the liver and our model suggests that antigen-specific immunotherapy may represent a powerful tool for treating liver tumors with characterized tumor-specific antigens. In addition, our data indicate that the number of E7-specific CD8+ T cell precursors directly correlated with the anti-tumor effect generated by Sig/E7/LAMP-1 vaccinia.     

Involvement of protein kinase A in cannabinoid receptor-mediated protection from oxidative neuronal injury

CB1 cannabinoid receptors (CB1Rs) are involved in protecting the brain from ischemia and related disorders. However, the underlying protective mechanisms are incompletely understood. We investigated the effect of CB1R activation on oxidative injury, which has been implicated in neuronal death after cerebral ischemia and neurodegenerative disorders, in mouse cortical neuron cultures. The CB1R agonist Win 55212-2 [R-(+)-[2,3-dihydro-5-methyl-3-[(morpholinyl)methyl]pyrrolo[1,2,3-de]-1,4-benzoxazin-yl]-(1-naphthalenyl)methanone mesylate] reduced neuronal death, measured by lactate dehydrogenase release, in cultures treated with 50 microM FeCl2, and its protective effect was attenuated by the CB1R antagonist SR141716A [N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-cichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide hydrochloride]. The endocannabinoid anandamide reproduced the effect of Win 55212-2, as did the antioxidant 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox). Neuronal injury was more severe after in vitro or in vivo administration of FeCl2 to CB1R-knockout compared with wild-type mice. Win 55212-2 reduced the formation of reactive oxidative species in cortical neuron cultures treated with FeCl2, consistent with an antioxidant action. Pertussis toxin reduced CB1R-mediated protection, which points to a protective mechanism that involves signaling through G(i/o) proteins. Since CB1R-activated G protein signaling inhibits protein kinase A but activates phosphatidylinositol 3-kinase (PI3K), we tested the involvement of these pathways in CB1R-mediated neuroprotection. Dibutyryl-cyclic adenosine monophosphate (dbcAMP) blocked protection by Win 55212-2, whereas the PI3K inhibitor wortmannin did not, and the effect of dbcAMP was inhibited by the protein kinase A inhibitor H89 [N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide] (> or =10 nM). CB1R-induced, SR141716A-, pertussis toxin-, and dbcAMP-sensitive protection was also observed for two other oxidative insults, exposure to H2O2 or buthionine sulfoximine. Therefore, receptor-stimulated inhibition of protein kinase A seems to be required for the neuroprotective effect of CB1R activation against oxidative neuronal injury.