An IFN-beta-albumin fusion protein that displays improved pharmacokinetic and pharmacodynamic properties in nonhuman primates.

The long half-life and stability of human serum albumin (HSA) make it an attractive candidate for fusion to short-lived therapeutic proteins. Albuferon (Human Genome Sciences [HGS], Inc., Rockville, MD) beta is a novel recombinant protein derived from a gene fusion of interferon-beta (IFN-beta ) and HSA. In vitro, Albuferon beta displays antiviral and antiproliferative activities and triggers the IFN-stimulated response element (ISRE) signal transduction pathway. Array analysis of 5694 independent genes in Daudi-treated cells revealed that Albuferon beta and IFN-beta induce the expression of an identical set of 30 genes, including 9 previously not identified. In rhesus monkeys administered a dose of 50 microg/kg intravenously (i.v.) or subcutaneously (s.c.) or 300 microg/kg s.c., Albuferon beta demonstrated favorable pharmacokinetic properties. Subcutaneous bioavailability was 87%, plasma clearance at 4.7-5.7 ml/h/kg was approximately 140-fold lower than that of IFN-beta, and the terminal half-life was 36-40 h compared with 8 h for IFN-beta. Importantly, Albuferon beta induced sustained increases in serum neopterin levels and 2',5' mRNA expression. At a molar dose equivalent to one-half the dose of IFN-beta, Albuferon beta elicited comparable neopterin responses and significantly higher 2',5'-OAS mRNA levels in rhesus monkeys. The enhanced in vivo pharmacologic properties of IFN-beta when fused to serum albumin suggest a clinical opportunity for improved IFN-beta therapy.     

The incidence and clinical implications of hypersensitivity to papain in an allergic population, confirmed by blinded oral challenge

Five hundred allergy clinic patients were prick skin tested with papain, 1 mg/mL, in addition to usual local aeroallergens. Five of 475 subjects with seasonal allergic disease had positive skin tests to both papain and local pollens. None of the 25 individuals with negative skin test to pollens had skin reactivity to papain. The five subjects with positive skin tests to papain underwent double-blind placebo-papain challenges. All papain challenges were positive. Placebo challenges were negative. Papain-induced symptoms included palatal itching, watering itchy eyes, sneezing, rhinorrhea, abdominal cramps, diarrhea, and diaphoresis. Circulating papain-specific IgE was detected in all the papain-sensitive individuals, but not in control subjects. Confirmed papain sensitivity occurred in 1.05% of allergic subjects. In the papain-sensitive patients, cross-reacting antibodies with chymopapain were found. The small number of non-allergic subjects did not show any papain or chymopapain sensitivity in vitro.     

Radiologic findings of Mirizzi syndrome with emphasis on MRI

We have reported a case of Mirizzi syndrome preoperatively diagnosed using MR cholangiopancreatography. MRCP and T2-weighted image using a single-shot fast spin-echo sequence accurately depicted all components of Mirizzi syndrome, including impacted stone in the neck of the gallbladder compressing the common hepatic duct and wall-thickening of the gallbladder without any evidence of malignancy. The combination of MRCP and T2-weighted image can be counted on to replace conventional modalities of diagnosing Mirizzi syndrome without any loss of diagnostic accuracy.     

Buoyant density in cesium chloride of the human reoviruslike agent of infantile gastroenteritis by ultracentrifugation,electron microscopy,and complement fixation

The buoyant density in cesium chloride of the human reoviruslike (HRVL) agent of infantile gastroenteritis was studied utilizing electron microscopy and complement fixation (CF) for the detection of reoviruslike particles in fractions of the density gradient. Three virus positive stool filtrates were studied. “Full” reoviruslike particles had a density of 1.35–1.37 g/cm³, whereas “empty” particles had a density of 1.29 g/cm³. Peak CF activity coincided with the peak fraction of both the “full” and “empty” reoviruslike particles. In addition, by differential centrifugation, CF activity was also associated with the virion and not a “soluble” antigen.     

Role for copper in transient oxidation and nuclear translocation of MTF-1, but not of NF-kappa B, by the heme-hemopexin transport system

Heme-hemopexin (2-10 microM) is used as a model for intravenous heme released in trauma, stroke, and ischemia-reperfusion. A transient increase in cellular protein oxidation occurs during receptor-mediated heme transport from hemopexin which is inhibited by the nonpermeable Cu(I) chelator, bathocuproinedisulfonate. Thus, participation of surface redox process involving Cu(I) generation are proposed to be linked to the induction of the protective proteins heme oxygenase-1 (HO-1) and metallothionein-1 (MT-1) by heme-hemopexin. The region (-153 to -42) in the proximal promoter of the mouse MT-1 gene responds to heme- and CoPP-hemopexin in transient transfection assays and contains metal-responsive elements for MTF-1 and an antioxidant-responsive element (ARE) overlapping a GC-rich E-box to which USF-1 and -2 bind. No decreases in DNA binding of the diamide-oxidation sensitive USF-1 and -2 occur upon exposure of cells to heme-hemopexin. MTF-1 and the ARE-binding proteins are relatively resistant to diamide oxidation and are induced approximately eight- and two-fold, respectively, by heme-hemopexin. BCDS prevents the nuclear translocation of MTF-1 by both heme- and CoPP-hemopexin complexes as well as MT-1 mRNA induction by CoPP-hemopexin. Thus, copper is needed for the surface oxidation events and yet the nuclear translocation of MTF-1 in response to hemopexin occurs via copper, probably Cu(I),-dependent signaling cascades from the hemopexin receptor rather than the oxidation per se.     

Preenhanced computed tomographic findings in brain death.

A patient complying with the clinical criteria for brain death was studied by preenhanced computed tomography (CT). Preenhanced CT showed apparent increased density at the base of the brain along the course of the major arterial vessels, and abnormally dense-appearing deep venous structures, like those of contrast-enhanced CT. There was a diffuse decrease in brain density with a poorly delineated ventricular system. These CT findings were very characteristic. CT as a non-invasive method seems to be valuable in the diagnosis of brain death. The relevant literature is reviewed and mechanisms showing those CT findings are discussed.     

Role of actin microfilament in osmotic stretch-induced increase of voltage-operated calcium channel current in guinea-pig gastric myocytes

 Using the whole-cell patch clamp technique, the role of actin microfilament in hyposmotic increase of voltage-operated calcium channel current (I _Ba) was studied in guinea-pig gastric myocytes. Hyposmotic superfusate (212 mOsm) increased peak I _Ba amplitude by 32.7 ± 6.5%; when cytochalasin-D (Cyt-D, 20 μM), an actin cytoskeleton disruptor, was used, an increase of only 9.7 ± 3.1% was seen. I _Baresponse to osmotic stress was potentiated (45.1 ± 4.1% increase) by 20 μM phalloidin, an actin microfilament stabilizer. However, colchicine (100 μM), an microtubule cytoskeleton disruptor, had no effect on either I _Ba or its response to hyposmotic solution. Phalloidin also induced a rightward shift of the I/V relationship of I _Ba, while Cyt-D itself had no effect. These results suggest that actin cytoskeleton may mediate hyposmotic stretch-induced I _Ba increase in gastric smooth muscle. Received: 26 March 1997 / Received after revision: 28 May 1997 / Accepted: 3 June 1997     

IFNgamma secretion following stimulation with total tumor peptides from autologous human tumors

Several issues remain to be resolved before the efficacy of various approaches to elicit anti-tumor immunity in patients can be evaluated. First, in vitro assays able to detect responses by T cells primed in vivo are needed. Second, a source of tumor antigen to stimulate patients' lymphocytes in vitro is required. The ELISPOT assay is attractive, because it can be performed with a small numbers of cells and requires only short-term culture in vitro. A source of tumor antigen is more problematic, since for most tumors, tumor-associated antigens (TAA) have not been identified and/or cloned. In this report we demonstrate that autologous antigen-presenting cells (APC) pulsed with total tumor peptides from autologous tumor tissue can stimulate IFNgamma release by patients' lymphocytes in the ELISPOT assay. Thus, this approach should be considered for monitoring immune responses in clinical immunotherapy trials.