Glycosylation and adhesiveness differentiate larval Ceratitis capitata tyrosinases

Larval Ceratitis capitata phenoloxidases (POs) from hemocytes, serum, integument, and fat body were analyzed. Two types of PO were recorded: the tyrosinase type found in hemocytes, serum, integument, and fat body and the laccase type found in integument. Tyrosinase from all larval tissues and integumental laccase as well, showed similarity in molecular weight (93 KDa), activation by Escherichia coli at 5 mM Ca²⁺, and reactivity to antibodies raised against serum tyrosinase. However, the enzymes differed with respect to their glycosylation and adhesiveness. The serum and integumental enzyme forms contain concanavalin A reacting material, whereas hemocyte and integumental tyrosinase(s) are adhesive. These differences in enzyme forms, although not influencing their substrate specificity, seem to give advantages to performing their function, i.e., the adhesive enzyme form facilitates the adherence to E. coli cell wall and hemocyte surface (unpublished data) while the glycosylated form facilitated the secretion into serum. © 1994 Wiley-Liss, Inc.     

Integrative structure of a 10-megadalton eukaryotic pyruvate dehydrogenase complex from native cell extracts

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IRAA: A statistical tool for investigating a protein–protein interaction interface from multiple structures

Understanding protein–protein interactions (PPIs) is fundamental to infer how different molecular systems work. A major component to model molecular recognition is the buried surface area (BSA), that is, the area that becomes inaccessible to solvent upon complex formation. To date, many attempts tried to connect BSA to molecular recognition principles, and in particular, to the underlying binding affinity. However, the most popular approach to calculate BSA is to use a single (or in some cases few) bound structures, consequently neglecting a wealth of structural information of the interacting proteins derived from ensembles corresponding to their unbound and bound states. Moreover, the most popular method inherently assumes the component proteins to bind as rigid entities. To address the above shortcomings, we developed a Monte Carlo method-based Interface Residue Assessment Algorithm (IRAA), to calculate a combined distribution of BSA for a given complex. Further, we apply our algorithm to human ACE2 and SARS-CoV-2 Spike protein complex, a system of prime importance. Results show a much broader distribution of BSA compared to that obtained from only the bound structure or structures and extended residue members of the interface with implications to the underlying biomolecular recognition. We derive that specific interface residues of ACE2 and of S-protein are consistently highly flexible, whereas other residues systematically show minor conformational variations. In effect, IRAA facilitates the use of all available structural data for any biomolecular complex of interest, extracting quantitative parameters with statistical significance, thereby providing a deeper biophysical understanding of the molecular system under investigation.     

The use of swine in brain interstitial radiation studies

Swine offer an excellent, but previously unused, model for brain interstitial ionizing and non-ionizing radiation research. Significant advantages include size, cost, maneuverability, availability and conditioning. The methodology and some experimental results from studies of the effects of interstitial microwave hyperthermia and iridium-192 irradiation are presented.     

Endocrine studies in postmenopausal women during oral replacement therapy with unconjugated oestrogens

Two groups of postmenopausal women were seen at monthly intervals during a three-month trial of continuous therapy with oral unconjugated oestrogens. Ten women in the first group were administered daily Hormonin No. 1 containing oestriol (E3) 0.135 mg, oestradiol (E2) 0.3 mg and oestrone (E1) 0.7 mg. Eight women in the second group received Hormonin No. 2 containing E3 0.27 mg, E2 0.6 mg and E1 1.4 mg. E1, E2, E3 and dehydroepiandrosterone (DHA) as well as follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were measured by radioimmunoassay. Maturation index of vaginal smears and clinical effects were also evaluated. Oral replacement therapy with these unconjugated oestrogens produced a significant elevation of E1 (p less than 0.05) and E2 (p less than 0.05) to values corresponding well with the premenopausal range measured in our laboratory. Postmenopausal levels of FSH and LH showed only a moderate but significant decrease (p less than 0.05). There was consistent relief of vasomotor symptoms. One case of endometrial focal adenomatous hyperplasia uncovered during the period of treatment was transformed to functional secretory endometrium after an appropriate course with progestogens. Oral administration of unconjugated oestrogens and periodic withdrawal bleeding induced with a progestational agent seems to be an effective method of replacement therapy in postmenopausal women.     

Hemorrhage associated with hepatic artery pseudoaneurysms after regional chemotherapy with floxuridine: case report

Pseudoaneurysms of the hepatic artery are a rare complication in patients with primary or secondary liver tumors treated with intra-arterial chemotherapy. We present two patients who developed this complication after placement of a catheter system into the gastroduodenal artery and initiation of regional chemotherapy with floxuridine. Diagnosis was made after symptomatic bleeding occurred, necessitating emergency angiography with coil embolization. Pseudoaneurysms usually occur after mechanical damage of the vessel wall, but the chemical toxicity of floxuridine may add to the development of vascular impairment.     

Increase in Phytase Activity and Decrease in Phytate During Germination of Four Common Legumes

Maximum phytase activity in four legume species, lentils, chick peas, broad beans and runner beans, was reached after 6 days of germination for chick peas and 8 days for the rest of them. In all legumes, the increase in phytase activity was accompanied by a concomitant decrease in phytate content. After 10 days of germination the decrease in phytate varied from 83% in broad beans up to 64% in runner beans.     

Morphogenetic effects of 9-cis-retinoic acid on the regenerating limbs of the axolotl

9-cis-retinoic acid has recently been found to be a high affinity ligand for the retinoic X receptor (RXR). RXRs are believed to be involved in metabolic activities rather than in morphogenetic ones. Interestingly, RXR has been found to form heterodimers involving other receptors from the steroid family, such as the thyroid hormone receptor, vitamin D receptor or retinoic acid receptors (RARs). In this paper we examined whether or not 9-cis-retinoic acid had any morphogenetic properties on the regenerating axolotl limb. It is shown that 9-cis-retinoic acid proximalized regenerating limbs and was somewhat more potent in this action than all-trans-retinoic acid. Based on these observations, the possible roles of other receptors during pattern formation is discussed. Correspondence to: P.A. Tsonis