Albumin-binding domain from Streptococcus zooepidemicus protein Zag as a novel strategy to improve the half-life of therapeutic proteins

Recombinant antibody fragments belong to the promising class of biopharmaceuticals with high potential for future therapeutic applications. However, due to their small size they are rapidly cleared from circulation. Binding to serum proteins can be an effective approach to improve pharmacokinetic properties of short half-life molecules. Herein, we have investigated the Zag albumin-binding domain (ABD) derived from Streptococcus zooepidemicus as a novel strategy to improve the pharmacokinetic properties of therapeutic molecules. To validate our approach, the Zag ABD was fused with an anti-TNFα single-domain antibody (sdAb). Our results demonstrated that the sdAb-Zag fusion protein was highly expressed and specifically recognizes human, rat and mouse serum albumins with affinities in the nanomolar range. Moreover, data also demonstrated that the sdAb activity against the therapeutic target (TNFα) was not affected when fused with Zag ABD. Importantly, the Zag ABD increased the sdAb half-life ∼39-fold (47min for sdAb versus 31h for sdAb-Zag). These findings demonstrate that the Zag ABD fusion is a promising approach to increase the half-life of small recombinant antibodies molecules without affecting their therapeutic efficacy. Moreover, the present study strongly suggests that the Zag ABD fusion strategy can be potentially used as a universal method to improve the pharmokinetics properties of many others therapeutics proteins and peptides in order to improve their dosing schedule and clinical effects.

[Cross-hand replantation in bilateral upper limb amputation: An anatomical emergency]

Bilateral amputations of upper limbs are excessively rare clinical situations. We report an exceptional clinical case of bilateral amputation of upper limbs at different levels: destruction of the right hand and left transhumeral amputation in a patient after an attempted suicide on train lines. This special situation led us to perform a cross-hand replantation of the left hand to the right forearm. Only 4 other similar cases have been published in the literature. Once the surgical indication had been formulated collectively, and taking into account all the ethical issues surrounding such a decision, we had to solve the issue of inverting anatomical structures in emergency. We have provided a detailed description of our surgical technique. The aim was to save at least one organ used for grasping. The result obtained is presented and reviewed.

Soft-tissue coverage of olecranon with musculocutaneous flexor carpi ulnaris flap

Coverage of the olecranon area is always challenging in traumatology. Because of the superficial situation of the bone, the absence of muscle, the thinness of the skin and the subcutaneous tissue locally, skin defects are not uncommon and can lead to exposure of hardware or prostheses. We report an original surgical technique using a musculocutaneous flap from the flexor carpi ulnaris (FCU) with a proximal pedicle to cover the olecranon area, detailing its limits and indications. The FCU flap has become our first-choice procedure to cover olecranon skin defects because of its low morbidity, its reliability, and its straightforward procedure, obviating the need for any microsurgery technique. Furthermore, it allows moving the elbow, immediately decreasing the risk of elbow stiffness.

Cholesterol content drives distinct pharmacological behaviours of micro-opioid receptor in different microdomains of the CHO plasma membrane

Cholesterol in the plasma membrane of eukaryotic cells contributes to modulating the functions and signalling pathways of numerous transmembrane proteins, including G protein Coupled Receptors (GPCRs). We have previously shown that the function of the human micro-opioid receptor (hMOR) expressed in Saccharomyces cerevisiae is modulated by sterols including cholesterol. Here, we investigated the effects of cholesterol content on hMOR pharmacology and on hMOR partitioning in cholesterol-poor and -rich domains in eukaryotic mammalian cells (CHO). We show that cholesterol is required for the stabilization of a receptor conformation with high agonist affinity and for triggering G-protein activation after agonist binding to the receptor. Biochemical analysis of untreated and cholesterol-depleted membranes in cells expressing hMOR indicated that the receptor is only present in cholesterol poor domains, in the basal state. After agonist binding to untreated CHO membranes, two distinct populations of receptor were found in cholesterol-rich and -poor domains. Cholesterol depletion or treatment of CHO membranes with the G-protein-decoupling agent GppNHp prevented the redistribution, indicating that receptor activated states localized into cholesterol-rich domains. Pharmacological data and biochemical analysis indicate that distinct activated conformations of hMOR exist in CHO plasma membrane and correspond to microdomains differing by thickness and proportions of lipid components, including cholesterol.

Effects of cGMP on calcium handling in ATP-stimulated rat resistance arteries

The mechanisms by which guanosine 3',5'-cyclic monophosphate (cGMP) modulates the contraction induced by ATP were investigated in small mesenteric resistance arteries of the rat. The nitric oxide donors 3-morpholinosydnonimine (SIN-1, 10 microM) and sodium nitroprusside (SNP, 10 microM) increased cGMP but not adenosine 3',5'-cyclic monophosphate (cAMP) content of the tissue. SIN-1, SNP, and 8-bromoguanosine 3',5'-cyclic monophosphate (8-BrcGMP, 100 microM) inhibited the myosin light chain phosphorylation and the contractile response to ATP. Both effects were completely reversed by the selective inhibitor of cGMP protein kinase, Rp-8-bromoguanosine 3',5'-cyclic monophosphorothioate (30 microM). The sensitivity to Ca2+ of arteries permeabilized with Staphylococcus aureus alpha-toxin (4,000 hemolytic units/ml) was not affected by 8-BrcGMP. The two nitric oxide donors and 8-BrcGMP decreased the rise in intracellular Ca2+ induced by ATP. The vasodilator agents abolished the contractile response to the exogenous calcium in vessels that were exposed to 3 mM ATP after depletion of intracellular Ca2+ stores. Thapsigargin (1 microM), an inhibitor of the sarcoplasmic reticulum Ca(2+)-adenosinetriphosphatase, reversed the inhibitory effect of the vasodilator agents when the contraction induced by ATP was elicited in the presence of the Ca2+ entry blocker nitrendipine (1 microM) or in Ca(2+)-free medium. These results show that cGMP inhibits ATP-induced contraction by decreasing intracellular Ca2+ concentration in small resistance arteries. They indicate that this effect results from decreased Ca2+ influx and enhanced Ca2+ sequestration through a thapsigargin-sensitive pump via activation of a cGMP protein kinase.

Effect of bacterial lipopolysaccharide on function of rat small femoral arteries

The effects of endotoxin on endothelial and smooth muscle function were investigated in small femoral arteries removed from rats 4 h after intraperitoneal injection of Escherichia coli lipopolysaccharide (LPS; 20 mg/kg) or solvent. In the absence of L-arginine in the organ bath, the sensitivity of the arteries to norepinephrine (NE) was decreased only slightly, and the relaxing effects of neither 3-morpholinosydonimine-N-ethyl-carbamide (SIN-1), a nitric oxide (NO) donor, nor acetylcholine (ACh) were modified by LPS treatment despite morphological damage to the endothelium seen with scanning electron microscopy. However, L-arginine (30 microM to 1 mM), which had no effect on control vessels, caused a rapid and stereospecific relaxation of arteries from LPS-treated rats that was abolished by both NG-nitro-L-arginine methyl ester (1 mM), a NO synthase inhibitor, and methylene blue, an inhibitor of the activation of guanylyl cyclase by NO. The relaxing effect of L-arginine was observed in the absence of endothelium, although it was significantly greater in its presence. In addition, a 30-min exposure to extracellular L-arginine (100 microM) moderately but significantly decreased the sensitivity to ACh and SIN-1 of vessels from LPS-treated but not from control rats. These results indicate that LPS treatment induced a NO synthase activity in smooth muscle cells of rat small femoral arteries and that the resulting relaxation was dependent on extracellular L-arginine in these resistance vessels.(ABSTRACT TRUNCATED AT 250 WORDS)

Left atrial myxoma in the elderly: diagnosis by M-mode and bidimensional echocardiography

Two cases are reported of left atrial myxoma in elderly patients, diagnosed by combined M-mode and bidimensional echocardiography. One patient was an 80-year-old man presenting with typical signs of mitral obstruction by an atrial tumor. His symptoms were erroneously attributed to chronic bronchitis until an echocardiogram was obtained. The other patient was a 70-year-old woman with atrial fibrillation of one year's duration. Left atrial myxoma, although rarely observed in the elderly, may be diagnosed easily by means of echocardiography. Some cases may prove amenable to surgical treatment.

The use of radio-immuno-inhibition assay for the study of the y, d and w determinants of hepatitis B surface antigen

A radioimmunoassay determination of the HBs antigen subtypes is discussed, it is simple but effective technique was used in association with the use of the Austria II kit (Abbott Laboratories). This method consists of an inhibition reaction of the Austria II test, by previous incubation of the antigen to be subtyped with a monospecific antibody. With this method we were able to distinguish the y and the d antigens as well as the w1, w3, w4 determinants of hepatitis B surface antigen. We have included a frequency table of the various HBs subtypes found among donor and patient populations in Liège.

Indefinite storage of dried Gm and Km (Inv) antigens: (examination of bloodstains 33 years old)

We confirm the great stability of the A and B antigens in dried blood, and the markedly lesser stability of antigen H. We demonstrate that it is possible to determine the immunoglobulin groups Gm(1), Gm(10) and Km(1)--formerly Inv(1)--in bloodstains 29 to 33 years old.

Identification of blood stains by non-genetic characteristics: the HBs antigen of viral hepatitis B

In forensic cases, until recently, identification of biological stains was based on the use of genetic markers, such as blood groups. In this paper, we show that another acquired characteristic, even if not immutable during life, may afford similar possibilities. As an example, we have demonstrated that the HBs antigen, associated with the hepatitis B virus, can help in the identification of bloodstains. The requisite condition for using this new marker, is that not too much time should elapse between the time the biological stains are formed and the moment when victim and suspected individual are examined for comparison of their blood with the stain. We have shown that in a dried state, the HBs antigen is very stable for a least six months. In vivo, it persists for a few week to 6 or 7 years according to thecase. HBs antigen is a relatively rate factor, its frequency being 0.5%ew marker, is that not too much time should elapse between the time the biological stains are formed and the moment when victim and suspected individual are examined for comparison of their blood with the stain. We have shown that in a dried state the, HBs antigen is very stable for a least six months. In vivo, it persists for a few week to 6 or 7 years according to the case. HBs antigen is a relatively rate factor its frequency being 0.5% in the Belgian population; the frequency reaches 2 to 3% in the Mediterranean population who constitute most of the immigrants in Belgium.

Polymorphism of the third component (C3) of complement and of Transferrin (Tf) in Belgium

The phenotypes of C3 and of Tf were determined in 818 and 576, respectively, unrelated individuals living in Liege. The gene frequencies observed are: (formula: see text) The application to disputed paternity cases and to the study of twins is discussed.

Nucleoside conformations. 15. Flexibility of natural pyrimidine nucleosides around the glycosidic bond

The flexibility of pyrimidine nucleosides has been investigated by measuring their circular dichroism in hydroalcoholic solutions over a large temperature range (-100 degrees to +40 degrees C). It was observed that ss-Uridine (Urd) and ss-Cytidine (Cyd) showed a decrease of the main dichroic band of about 40 percent, while sterically hindered nucleosides (alphaUrd, ara-Uracile, 02-2' anhy-dro-Urd, 2'3'-0-isopropylidene-Urd) showed only small decreases. It is concluded that the flexibility of the glycosidic linkage in conjunction with the pseudo-rotation of the sugar residue is responsible for these changes; the thermodynamic values which can be deduced from these decreases are compatible with an oscillatory motion around the glycosidic bond, but exclude anti-syn transformations in pyrimidine nucleosides.