Antioxidative activity of summer savory (Satureja hortensis L.) and rosemary (Rosmarinus officinalis L.) in minced, cooked pork meat

The sensory intensity measured as theabsolute threshold value of spice andrecognition of spice was evaluated for summer savory and rosemary in meat balls. The values forabsolute threshold value of spice were found to be significantly lower for rosemary than for summer savory. The antioxidative activity of the spices was analysed in two accelerated model systems and in a storage experiment. In one of the model systems, oxidation was accelerated by heat and by an elevated pressure of oxygen. Both spices significantly improved the oxidative stability of the meat balls in this model system. In the second model system metal catalyst oxidation in a meat slurry was used and a reduction in the oxidative processes in samples containing the spices was again shown. In both model systems a slightly higher antioxidative activity was seen for rosemary compared to summer savory. In the storage experiment, the spices were added at a sensorially acceptable level and the heat-treated meat balls were stored at 5°C. A significant reduction in the development of warmed-over flavour (WOF) caused by the addition of spices was measured by a reduction in 2-thiobarbituricacid-reactivesubstances (TBARS) and in hexanal. A reduction in TBARS of approximately 30% in meat balls containing added spices was seen independently of packaging in 1% oxygen or in atmospheric air and the reduction (30%) was constant throughout the storage period.     

Follicular and Hurthle cell carcinomas of the thyroid: a comparative study

University of Texas M. D. Anderson Cancer Center cases filed as Hurthle cell and follicular carcinoma were reviewed. Requirements for including a case in the study were that the diagnosis of Hurthle cell or follicular carcinoma be confirmed, that histologic material and clinical information be adequate, and that there be at least 9 years of follow-up. The study group included 18 cases of Hurthle cell carcinoma and 33 cases of follicular carcinoma. Ten of the Hurthle cell carcinomas had extrathyroid invasion, three had intrathyroid invasion, and five were encapsulated (i.e., they had intracapsular invasion only). In the follicular carcinoma group, 5 tumors had extrathyroid invasion, 14 had intrathyroid invasion, and 14 were encapsulated. When the cases were stratified according to extent of invasion in this manner, there was no statistically significant difference in rate of local recurrence, rate of metastasis (either regional lymph node or distant), or patient survival between Hurthle cell carcinoma and follicular carcinoma. Other variables including patient age and sex, treatment differences, tumor size, vascular invasion, predominant growth pattern (follicular versus solid-trabecular), nuclear size and pleomorphism, mitotic rate, and tumor necrosis did not provide significant additional prognostic information. Metastases of both Hurthle cell and follicular carcinoma were mostly distant and predominantly involved bone and lung. Behavioral differences between Hurthle cell and follicular carcinoma that were not statistically significant included a higher rate of local recurrence in Hurthle cell carcinoma with intrathyroid invasion, more frequent occurrence of regional lymph node metastasis in Hurthle cell carcinoma with extrathyroid invasion, and absence of distant metastasis and death caused by tumor in encapsulated Hurthle cell carcinoma. Five follicular carcinomas and one Hurthle cell carcinoma appeared to have arisen within an adenoma.     

Internal cleavage of the inhibitory 7B2 carboxyl-terminal peptide by PC2: a potential mechanism for its inactivation

The neuroendocrine protein 7B2 contains two domains, a 21-kDa protein required for prohormone convertase 2 (PC2) maturation and a carboxyl-terminal (CT) peptide that inhibits PC2 at nanomolar concentrations. To determine how the inhibition of PC2 is terminated, we studied the metabolic fate of the 7B2 CT peptide in RinPE-7B2, AtT-20/PC2-7B2, and alphaTC1-6 cells. Extracts obtained from cells labeled for 6 h with [3H]valine were subjected to immunoprecipitation using an antibody raised against the extreme carboxyl terminus of r7B2, and immunoprecipitated peptides were separated by gel filtration. All three cell lines yielded two distinct peaks at about 3.5 kDa and 1.5 kDa, corresponding to the CT peptide and a smaller fragment consistent with cleavage at an interior Lys-Lys site. These results were corroborated using a newly developed RIA against the carboxyl terminus of the CT peptide which showed that the intact CT peptide represented only about half of the stored CT peptide immunoreactivity, with the remainder present as the 1.5-kDa peptide. Both peptides could be released upon phorbol 12-myristate 13-acetate stimulation. We investigated the possibility that PC2 itself could be responsible for this cleavage by performing in vitro experiments. When 125I-labeled CT peptide was incubated with purified recombinant PC2, a smaller peptide was generated. Analysis of CT peptide derivatives for their inhibitory potency revealed that CT peptide 1-18 (containing Lys-Lys at the carboxyl terminus) represented a potent inhibitor, but that peptide 1-16 was inactive. Inclusion of carboxypeptidase E (CPE) in the reaction greatly diminished the inhibitory potency of the CT peptide against PC2, in line with the notion that the CT peptide cleavage product is not inhibitory after the removal of terminal lysines by CPE. In summary, our data support the idea that PC2 cleaves the 7B2 CT peptide at its internal Lys-Lys site within secretory granules; deactivation of the cleavage product is then accomplished by CPE, thus providing an efficient mechanism for intracellular inactivation of the CT peptide.     

Interleukin 4, interferon-gamma, and prostaglandin E impact the osteoclastic cell-forming potential of murine bone marrow macrophages

Interleukin 4 (IL-4) is an immune cytokine that inhibits bone resorption in mice and suppresses osteoclastic cell formation in vitro through an undefined mechanism. In this report, we have established the cellular identity of the IL-4 target cell using a variety of bone marrow/stromal cell coculture methods. Initially, we found that the majority of IL-4's inhibition of osteoclastic cell formation was due to its effect on bone marrow cells, not stromal cells. Consequently, bone marrow macrophages were used as osteoclastic cell progenitors after they had been transiently exposed to IL-4 (48 h), before the addition of stromal cells, 1,25-dihydroxyvitamin D3, and dexamethasone. In this circumstance, IL-4 impaired subsequent osteoclastic cell formation, suggesting that the macrophage may be potentially targeted by many factors known to influence osteoclast formation. Consequently, we discovered that interferon-gamma (IFN gamma), prostaglandin E (PGE), and cell-permeant cAMP analogs also impacted osteoclastic cell formation when used to selectively treat bone marrow macrophages. IFN gamma suppressed osteoclastic cell formation, whereas PGE and cAMP analog treatment led to the formation of significantly enlarged osteoclastic cells. Importantly, PGE antagonized the inhibitory effects of both IL-4 and IFN gamma on the osteoclastic cell-forming potential of bone marrow macrophages. Collectively, these findings establish bone marrow macrophages as osteoclastic cell precursors with the degree of their commitment to the osteoclast pathway sensitive to the effects of soluble mediators, including IL-4, IFN gamma, and PGE.     

Antithrombins Wibble and Wobble (T85M/K): archetypal conformational diseases with in vivo latent-transition, thrombosis, and heparin activation

The inherent variability of conformational diseases is demonstrated by two families with different mutations of the same conserved aminoacid in antithrombin. Threonine 85 underlies the opening of the main beta-sheet of the molecule and its replacement, by the polar lysine, in antithrombin Wobble, resulted in a plasma deficiency of antithrombin with an uncharacteristically severe onset of thrombosis at 10 years of age, whereas the replacement of the same residue by a nonpolar methionine, antithrombin Wibble, gave near-normal levels of plasma antithrombin and more typical adult thromboembolic disease. Isolated antithrombin Wibble had a decreased thermal stability (Tm 56.2, normal 57.6 degreesC) but was fully stabilized by the heparin pentasaccharide (Tm 71.8, normal 71.0 degreesC), indicating that the prime abnormality is a laxity in the transition of the main sheet of the molecule from the 5- to 6-stranded form, as was confirmed by the ready conversion of antithrombin Wibble to the 6-stranded latent form on incubation. That this transition can occur in vivo was shown by the finding of nearly 10% of the proband's plasma antithrombin in the latent form and also, surprisingly, of small but definitive amounts of latent antithrombin in normal plasma. The latent transition will be predictably accelerated not only by gross mutations, as with antithrombin Wobble, to give severe episodic thrombosis, but also by milder mutations, as with antithrombin Wibble, to trigger thrombosis in the presence of other predisposing factors, including the conformational stress imposed by the raised body temperatures of fevers. Both antithrombin variants had an exceptional (25-fold) increase in heparin affinity and this, together with an increased inhibitory activity against factor Xa, provides evidence of the direct linkage of A-sheet opening to the conformational basis of heparin binding and activation.     

Effective use of ribonucleotide reductase inhibitors (Didox and Trimidox) alone or in combination with didanosine (ddI) to suppress disease progression and increase survival in murine acquired immunodeficiency syndrome (MAIDS)

Ribonucleotide reductase inhibitors (RRIs) have been recently shown to inhibit retroviral replication. We examined a new series of RRIs, 3,4-dihydroxybenzohydroxamic acid (Didox) and 3,4,5-trihydroxybenzohydroxamidoxime (Trimidox) for their ability to alter disease progression in murine acquired immunodeficiency syndrome (MAIDS), both alone and in combination with 2',3'-dideoxyinosine (ddI). MAIDS disease was induced by inoculation of female C57BL/6 mice with the LP-BM5 murine leukemia virus (MuLV) and disease progression characterized by extensive peripheral lymphadenopathy and splenomegaly. Efficacy of treatment with these drugs was based upon their ability to influence survival and disease pathophysiology by monitoring the development of splenomegaly. Toxicity was determined by changes in body weight, total peripheral white blood cell count and hematocrit. Didox or trimidox monotherapy was associated with increased survival and decreased disease pathophysiology, with no apparent toxicity. Combined with ddI, their ability to reduce development of viral induced splenomegaly was enhanced compared to trimidox, didox or ddI alone. These results demonstrate RRIs have potent activity in reversing the disease manifestations characteristic of MAIDS. Further studies are warranted to determine human clinical efficacy.