Dinuclear calcium complex with weakly NH...O hydrogen-bonded sulfonate ligands.

The novel intramolecularly NH...O hydrogen-bonded Ca(II)-aryl sulfonate complex, [Ca2(SO3-2-t-BuCONHC6H4)2(H2O)4]n(2-t-BuCONHC6H4SO3)2n (1), sulfonate anion, (HNEt3)(SO3-2-t-BuCONHC6H4) (2a), (PPh4)(SO3-2-t-BuCONHC6H4) (2b), (n-Bu4N)(SO3-2-t-BuCONHC6H4) (2c), and sulfonic acid, 2-t-BuCONHC6H4SO3H (3), were synthesized. The structures of 1, 2a, and 2b depict the presence of the formation of NH...O hydrogen bonds between the amide NH and S-O oxygen for a series of compounds as determined by IR and 1H NMR analyses both in the solid state and in the solution state. Thus, the NH...O hydrogen bonds with neutral amide groups are available for investigation of the electronic state of the O- anion. The combined data from the IR and 1H NMR spectra indicate that the sulfonic acid, sulfonate anion, and Ca(II) complex have a substantially weak intramolecular NH...O hydrogen bond between the SO3 oxygen and amide NH. In the detailed comparison with the intense NH...O hydrogen bonds for the carboxylate, weak NH...O hydrogen bonds for sulfonate is due to the strong conjugation of the SO3- group with the lower nucleophilicity.

Abstinence from drink ameliorated cerebral blood flow and vasoreactivity in patients with chronic alcoholism.

High dose ethanol consumption is a risk factor for both ishemic and hemorrhagic cerebrovasucular disease. This link between heavy drinkers and the risk factor of stroke has been considered as hypertension, liver dysfunction, abnormality of platelet function or other unknown mechanisms. Recently some of the experimental study suggest that direct action of ethanol on the inhibition of the synthesis/release of nitric oxide from endothelium and neurons may contribute to this link. Few studies in this field, however, were performed clinically. We examined cerebral blood flow (CBF) and vaso-reactivity in the patients with chronic alcoholism on abstinence from drink. CBF of nine male patients were measured by use of stable Xe-CT method before and after acetazolamide load. Regional CBF increased in second measurement after abstinence, but there were no significant changed statistically. However, %vaso-reactivity in right ACA and MCA significantly improved. We considered that large brain vessels dilated then small vessels could response to acetazolamide.

A specific thrombin inhibitor (argatroban) ameliorated cerebral blood flow in the patients with acute cerebral infarction.

Argatroban, one of the arginine derivatives, has been reported to have a safe and potent antithrombin action. This compound is active in several animal models of thrombosis and also has been shown to improve general neurological symptomatology, general subjective symptomatology and general daily behavior in the patients with acute thrombosis. This was considered to reflect remarkable improvement of microcirculation. No published clinical data, however, exist on the effect of argatroban on cerebral blood flow (CBF) change during acute stroke. Three patients with acute cerebral infarction were subjected to this study. Intravenous argatroban injection (2.5 mg/hr) was continued in 48 hours. Regional CBF (rCBF) was measured before and after injection of argatroban using Xe-CT method. Argatroban increased CBF not only in the injured side hemisphere or penumbra, but also contralateral side of lesion in the patients with acute cerebral infarction.

[Changes in the level of thrombomodulin with aging].

Thrombomodulin (TM) is a thrombin receptor on endothelial cells. When endothelial cells are damaged TM is degraded and released into the blood. We examined whether levels of TM in plasma reflect endothelial damage related to aging. We measured the TM level in samples of plasma from 93 healthy men aged from 22 to 81 years. None had hypertension, obesity, diabetes mellitus, or cardiovascular disease. The relationship between the level of TM (Y) and age (X) could be approximated by Y = 0.176X + 10.379, the correlation was significant (r = 0.647, p < 0.01). Basal levels of TM in subjects from 20 to 60 years old showed a gradual increase, that was not statistically significant. Basal concentrations of TM were significantly higher in the older subjects than in the younger subjects. The high levels of TM in the older subjects might reflect endothelial damage. In conclusion, a high TM level in plasma may be a sign of endothelial damage related to aging.

Effects of amino acids on the growth of an anaerobic rumen fungus Neocallimastix sp N 13.

The amino acid requirements of Neocallimastix sp N 13 isolated from sheep rumen were studied using supplements containing either ten essential amino acids (10 EAA) or eight nonessential amino acids (8 NEAA), or both (18 AA). Although the fungus could grow in a medium containing ammonium sulphate as the sole source of nitrogen, amino acid supplements, especially 18 AA, greatly stimulated its growth. Omission of the sulphur-containing amino acids (SCAA) from the 18 AA mixture markedly reduced the growth-stimulating effect, and sulphide, but not sulphate, substituted for SCAA only partly compensated for this omission. Omission of aromatic, branched chain, basic, acidic, aliphatic and hydroxy amino acids, and proline, singly or in combination, all reduced fungal growth to some degree as compared with the 18 AA supplement. A three amino acid (leucine, methionine and histidine) supplement was a potent stimulator for the fungus, whereas another three amino acid combination (glutamic acid, methionine and serine) was ineffective. The results indicated that Neocallimastix sp N 13 effectively utilized amino acids for its growth, but the requirements for the different amino acids differed from those of N patriciarum.

Effects of some ionophore antibiotics and polyoxins on the growth of anaerobic rumen fungi.

The growth of mixed rumen fungi in vitro was suppressed by both ionophore antibiotics (salinomycin, monensin and portmicin) and polyoxins (polyoxin B and D: inhibitors of chitin synthesis). The fungistatic effect of the ionophores on a Piromonas spp. was more pronounced than on a Neocallimastix spp. The polyoxins, however, were more potent fungistatically against the Neocallimastix spp. than the Piromonas spp. Higher concentrations of the polyoxins were required to elicit the same effect as that observed with the ionophores. Salinomycin administration decreased fungal count in the rumen of sheep, but fungal count increased after the cessation of the feeding of the antibiotic. Polyoxin D also suppressed the growth of fungi in vivo, but the effect was short-lived. Nevertheless, both bacterial and protozoal counts tended to increase during and after the administration of polyoxin D. Total volatile fatty acid concentrations in the rumen tended to increase during the period of polyoxin D administration. This increasing tendency was maintained for 10 d after the cessation of antibiotic administration. Offering polyoxin D to sheep increased production of propionate (P < 0.05), while decreasing that of acetate. The results indicate that the rumen fungi are sensitive to chitin synthesis inhibitors as well as ionophores, and are essential members of microbes in the rumen ecosystem.