Stability of Interleukin 1β (IL-1β) in Aqueous Solution: Analytical Methods,Kinetics, Products,and Solution Formulation Implications

The thermal stability of IL-1 in aqueous solution as a function of temperature (5–60°C), pH (2–9), buffer (acetate, citrate, tris, and phosphate), and cyroprotectants (sugars, HSA) was investigated in this study. The analytical methodologies included RP-HPLC, SEC, ELISA, IEF-PAGE, SDS-PAGE, and bioassay. The degradation and inactivation of IL-1 at or above 39°C were attributed to autoxidation of the two cysteine residues in the denatured protein, followed by hydrophobic/covalent aggregation and precipitation. At or below 30°C, IEF- and SDS-PAGE results suggest a possible deamidation reaction. The difference in mechanism of degradation precludes the prediction of formulation shelf life from accelerated temperature data. Nonetheless, the good stability observed at 5°C suggests that a solution formulation may be feasible for IL-1.     

Circadian and sleep/wake dependent aspects of subjective alertness and cognitive performance

Circadian and sleep/wake dependent processes underlying variations in subjective alertness and cognitive performance were assessed in a constant routine protocol and in a protocol in which the sleep/wake cycle was uncoupled from the output of the endogenous circadian pacemaker. In the latter protocol, the contribution of a sleep/wake dependent process and a circadian process to alertness and performance were separated by folding the data at either the period of the sleep/wake cycle or at the period of the endogenous circadian body temperature rhythm. This analysis revealed that prior wakefulness within a range of 0-18 h significantly reduced alertness and performance and that the circadian rhythm of core body temperature paralleled the circadian rhythm of alertness and performance. During the first 16 h of the constant routine protocol, which coincided with the subjects' habitual period of wakefulness, alertness and performance remained at a stable level. The latter finding was explained by assuming that during our usual waking day the circadian system counteracts the detrimental effects of increasing duration of prior wakefulness.     

Endoscopic reappraisal of the morphology of congenital obstruction of the posterior urethra.

Congenital obstruction of the posterior urethra was first systematically classified by Young in 1919. Since then, no-one has seriously challenged the presence of both Type I and Type III "valves", although the presence of Type II lesions has often been disputed. A review of Young's papers and more recent anatomical studies, together with endoscopic findings in our own patients, indicates that most congenital posterior urethral obstructions are anatomically similar. Consequently, Young's classification now seems redundant.     

Chimerism in peripheral blood of sensitized patients waiting for renal transplantation: clinical implications

BACKGROUND: Potential renal transplant recipients with preformed antibodies to HLA resulting from previous transplants, pregnancy, and/or transfusions are unlikely to receive an allograft. The factors contributing to the long-term maintenance of antibody titers in these individuals are still unknown. In the present study, we sought to determine whether chimerism in the blood correlates with maintenance of HLA sensitization in highly sensitized patients. METHODS: Qualitative analysis of chimerism in blood of sensitized patients was assessed by polymerase chain reaction-sequence specific oligonucleotide probes (PCR-SSOP) to HLA-DR. PCR single-strand conformation polymorphism (PCR-SSCP) was used to confirm the extra HLA-DR antigens detected by PCR-SSOP. RESULTS: Fourteen of 36 patients (38.9%) were positive for more than two HLA-DR indicative of chimerism. The presence of extra HLA-DR was confirmed by PCR-SSCP. When patients were analyzed on the basis of their panel-reactive antibody (PRA) status, 10 of 15 (66.7%) were positive for chimerism in the sensitized group, compared with only two of eight (25%) in the unsensitized group. Of the five males in the sensitized group who had received a blood transfusion but not a transplant, three were positive for chimerism. An association was observed between chimerism and maintenance of sensitization. None of the eight normal subjects studied demonstrated chimerism. CONCLUSIONS: The results obtained with sensitized patients suggest an association between blood chimerism and maintenance of HLA sensitization. We speculate that chimerism may lead to long-term maintenance of anti-HLA antibody titers. This finding implies that abolition of chimerism could result in the eventual elimination of antigenic stimuli for antibody production against HLA antigens.     

Sevoflurane and anesthesia for neurosurgery: a review

This review assesses the extent to which sevoflurane fulfills the requirements of the ideal inhalational agent for use in neuroanesthetic practice. Sevoflurane's pharmacokinetic profile is outlined. Data from animal and human studies are used to discuss its effects on cerebral hemodynamics, central nervous system monitoring, and cardiovascular parameters. Where possible, sevoflurane is compared with isoflurane, currently considered the inhalational agent of choice in neuroanesthesia. Sevoflurane's potential for toxicity is reviewed.     

Evidence for cytotoxic T lymphocyte response against human lung cancer: reconstitution of antigenic epitope with peptide eluted from lung adenocarcinoma MHC class I

BACKGROUND: Cancer-associated, major histocompatibility complex (MHC)-restricted peptide antigens have been elucidated in human melanomas and ovarian, breast, and renal carcinomas; but relatively little is known about lung cancer antigens. METHODS: To work toward delineation of lung cancer-associated antigens, we developed tumor infiltrating lymphocytes (TILs), peripheral blood mononuclear cell-derived cytolytic T cell lines (CTL), autologous lung cancer cell lines, and normal lung cell lines from 17 patients undergoing lung cancer resections. The TILs and CTL lines were subsequently evaluated for markers of activation and specific lysis of autologous or allogeneic lung cancer cell lines or both. RESULTS: Freshly isolated TILs contained a more activated T cell population compared with the patients' peripheral blood T cells as evidenced by an increased expression of HLA-DR, CD25, and CD45RO. TILs isolated from 15 patients lysed allogeneic lung cancer lines. TILs lysed autologous lung cancer but not autologous normal lung or Epstein-Barr virus transformed B cell lines (B-LCL) in 4 of 8 cases tested, suggesting tumor specificity. A CTL line (RHPBL57.1) was generated from peripheral blood mononuclear cells of an HLA-A24(+) patient by stimulation against an established HLA-A24(+) allogeneic lung cancer cell line. RHPBL57.1 lysed the lung cancer cell line in an HLA-A24-restricted manner. Moreover, RHPBL57.1 specifically lysed autologous B-LCL pulsed with peptides, eluted from MHC class I and isolated from the HLA-A24(+) lung cancer cell line. CONCLUSIONS: TILs isolated from patients with lung cancer are predominantly an activated population of T cells with evidence of tumor and MHC class I-restricted lysis. Furthermore, we provide evidence for a lung cancer-associated, MHC class I-bound peptide antigen(s) that reconstitutes the epitope recognized by a lung cancer specific CD8(+) T cell line derived from a patient with lung cancer.     

The relationship between dietary fat intake and risk of colorectal cancer: evidence from the combined analysis of 13 case-control studies

The objective of this study was to examine the effects of the intakeof dietary fat upon colorectal cancer risk in a combined analysis of datafrom 13 case-control studies previously conducted in populations withdiffering colorectal cancer rates and dietary practices. Original datarecords for 5,287 cases of colorectal cancer and 10,470 controls werecombined. Logistic regression analysis was used to estimate odds ratios (OR)for intakes of total energy, total fat and its components, and cholesterol.Positive associations with energy intake were observed for 11 of the 13studies. However, there was little, if any, evidence of anyenergy-independent effect of either total fat with ORs of 1.00, 0.95, 1.01,1.02, and 0.92 for quintiles of residuals of total fat intake (P trend =0.67) or for saturated fat with ORs of 1.00, 1.08, 1.06, 1.21, and 1.06 (Ptrend = 0.39). The analysis suggests that, among these case-control studies,there is no energy-independent association between dietary fat intake andrisk of colorectal cancer. It also suggests that simple substitution of fatby other sources of calories is unlikely to reduce meaningfully the risk ofcolorectal cancer.     

Semi-quantitation of urokinase plasminogen activator and its receptor in breast carcinomas by immunocytochemistry.

Urokinase plasminogen activator (uPA) is a serine protease involved in cancer invasion and metastasis. uPA acts in vivo by binding to a membrane receptor known as uPAR. In this study, uPA and uPAR levels were semiquantitated by immunocytochemistry in 36 primary breast carcinomas. Using monoclonal antibody HD-UK 1, uPA was detected both in stromal and in malignant cells. However, the predominant location was in the stromal cells. Using double-staining, cells containing uPA were also found to coexpress either cytokeratin (an epithelial cell marker) or more frequently KP1 (a macrophage/monocyte cell marker). With monoclonal antibody HD-uPAR 13.1, uPAR was localized principally to spindle- or macrophage-like stromal cells, especially when these cells surrounded invasive breast cancer. In contrast, uPAR was only rarely detected in cancer cells and was not detected in normal epithelia surrounding tumour or in areas of adenosis. uPA levels in both stromal and epithelial cells were significantly correlated with those for uPAR. We conclude that both uPA and its receptor are mostly present in stromal cells in invasive breast carcinomas. These results suggest that stromal cells collaborate with malignant cells to mediate metastasis.     

Assay of matrix metalloproteinases types 1, 2, 3 and 9 in breast cancer.

Matrix metalloproteinases (MMPs) are zinc dependent endopeptidases implicated in cancer invasion and metastasis. Gelatin zymography was performed on 84 human breast carcinomas and seven normal breast tissues. The precursor form of MMP-2 (72 kDa) was found in 11 (12%) samples, while its two activated forms, i.e. 62 kDa and 59 kDa, were found in three (6%) and 34 (40%) samples respectively. In contrast to MMP-2, most of the samples (52%) contained MMP-9 in its precursor form. Using ELISA, MMP-1 levels were found in 12% of the samples while MMP-3 levels were found in only 2% of the samples. Levels of MMP-2, -3 and -9 correlated inversely with numbers of nodal metastases. Neither MMP-2 nor -9 levels were significantly related to patient outcome. However, patients with high levels of a 50-kDa gelatinase band after zymography had a significantly better survival than patients with low levels. This species was never observed in normal breast tissue.